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difficulty
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800,270
AMR-119-0066
Several Complex Variables Problem List — Problem 69
Is the support of $\mu$ equal to the closure of the repelling periodic orbits?
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 69 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
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null
null
null
null
null
null
null
null
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null
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null
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null
null
null
null
800,271
AMR-119-0067
Several Complex Variables Problem List — Problem 70
Does there exist a holomorphic map $F:\mathbb{P}^k \rightarrow \mathbb{P}^k$ with a wandering Fatou component $U$, i.e. $F^n(U) \bigcap F^m(U) = \emptyset $ for all $n \neq m$?
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 70 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
800,272
AMR-119-0068
Several Complex Variables Problem List — Problem 71
Classify the dynamics around a fixed point of a holomorphic map on $\mathbb{P}^k$ or even just defined in a neighborhood of p. -sibony@anh.matups.fr
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 71 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
800,273
AMR-119-0069
Several Complex Variables Problem List — Problem 72
Let $f:\mathbb{P}^2 \rightarrow \mathbb{P}^2$ be a holomorphic map of degree $d \geq 2$. Assume K is a totally invariant set. Let C denote the critical set of $f$. Assume $\overline{\bigcup_{n=1}^{\infty} f^n(C)} \bigcap K = \emptyset$. Is f hyperbolic on K?
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 72 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
800,274
AMR-119-0070
Several Complex Variables Problem List — Problem 73
Let $H_d$ denote the space of holomorphic maps $f:\mathbb{P}^2 \rightarrow \mathbb{P}^2$ of degree d. This is a finite dimensional space parametrized by the coefficients. Does the set of $ f\in H_d$ with infinitely many attractive basins have measure zero?
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 73 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
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null
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null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
800,275
AMR-119-0071
Several Complex Variables Problem List — Problem 74
Let $f:\mathbb{P}^2 \rightarrow \mathbb{P}^2$ be a holomorphic map of degree $d \geq 2$ and let $\lambda_1 \leq \lambda_2$ be the Lyapunov exponents for the ergodic measure $\mu = T \wedge T$. Is $\lambda_1 >0$?
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 74 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
null
null
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null
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null
800,276
AMR-119-0072
Several Complex Variables Problem List — Problem 76
Is every compact reduced analytic space biholomorphically equivalent to a subvariety of a complex manifold? If so, can the manifold be chosen to be compact?\\ -E. L. Stout, stout@math.washington.edu
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 76 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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800,277
AMR-119-0073
Several Complex Variables Problem List — Problem 77
Let C be a smooth cubic in $\mathbb{P}^2$. Then $\mathbb{P}^2\setminus C$ is algebraically parallellizable, but cannot be algebraically immersed in $\mathbb{C}^2$. Can it be holomorhically immersed in $\mathbb{C}^2$? [ There are smooth cubics for which it is true . For related problems see the section called ``Stein ma...
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 77 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
800,278
AMR-119-0074
Several Complex Variables Problem List — Problem 78
Consider the following statement: `` Let Y be a compact subset of $\mathbb{C}^2$ which lies over the circle $|\lambda|= 1$, and let U be an open neighborhood of K, the polynomially convex hull of Y. Then there exists a finitely sheeted Riemann surface S lying over $|\lambda| < 1$ as a branched covering such that $S\sub...
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 78 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,279
AMR-119-0075
Several Complex Variables Problem List — Problem 79
Let M be a K$\ddot{a}$hler manifold. Assume that all curvatures are between $-a^2$ and $-b^2$. Construct nontrivial bounded holomorphic functions on M.\\ -N. Sibony, sibony@anh.matups.fr
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 79 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
null
null
null
null
null
800,280
AMR-119-0076
Several Complex Variables Problem List — Problem 80
Are strongly pseudoconvex CR surfaces of real dimension 5 locally embeddable?
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 80 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
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null
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null
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null
800,281
AMR-119-0077
Several Complex Variables Problem List — Problem 81
Let $M \subset P^n$ be a compact odd dimensional CR manifold. Find conditions on M which ensure that M bounds a complex variety.(This is well understood in $\mathbb{C}^n$.)\\ -N.Sibony, sibony@anh.matups.fr
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 81 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
800,282
AMR-119-0078
Several Complex Variables Problem List — Problem 82
**(New) (Liouville type assertion on CR 3-manifolds) On a CR 3-manifold one can always define a Carnot-Caratheodory metric. A homeomorphism between two strongly pseudoconvex CR 3-manifolds is called conformal if it maps infinitesimal spheres with respect to a Carnot-Caratheodory metric to infinitesimal spheres. Is a co...
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 82 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
null
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null
null
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null
800,283
AMR-119-0079
Several Complex Variables Problem List — Problem 83
**(New) A diffeomorphism between two strongly pseudoconvex CR $(2n+1)$-manifolds is called quasiconformal if its differential preserves the underlying contact structures and distorts the CR structures boundedly. When Hermitian metrics on the contact bundles are fixed, this distortion can be measured by checking how sph...
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 83 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
null
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null
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null
null
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null
800,284
AMR-119-0080
Several Complex Variables Problem List — Problem 84
Let $\Omega \subseteq \mathbb{C}^n$ be a bounded domain with complete Kobayashi metric. Is there a constant $C = C(p) > 0$ such that if $f$ is holomorphic and $p > 0$ then for all $z \in \Omega$ and all $r > 0$ small it holds that $$ |f(z)|^p \leq C \frac{1}{|B(z,r)|} \int_{B(z,r)} |f(\zeta)|^p dV(\zeta) . $$ Here $f$ ...
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 84 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
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null
null
null
null
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null
800,285
AMR-119-0081
Several Complex Variables Problem List — Problem 85
Prove that if $\Omega$ is strongly pseudoconvex then there is an absolute constant $K > 0$ such that the integrated Kobayashi distance between any two points can be realized by a Kobayashi chain of $K$ discs. [For instance, on a convex domain, $K = 1.$] \\ Prize \$50 -S. Krantz. sk @math.wustl.edu
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 85 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,286
AMR-119-0082
Several Complex Variables Problem List — Problem 86
Prove that if $\Omega$ is a smooth bounded pseudoconvex domain in $\mathbb{C}^n$ which is finite type in the sense of D'Angelo, then it is of finite type in the sense of Kohn (ideal type).\\ Prize \$50 -J. McNeal, mcneal@math.princeton.edu
Source list: Buzzard, Fornaess, Krantz - The Several Complex Variables Problem List (1995) Source item: Problem 86 Source URL: https://arxiv.org/abs/math/9509202 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Buzzard, Fornaess, Krantz
1,995
8
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 8, "name": "analysis", "display_name": "Analysis", "description": "Limits, continuity, calculus, and function theory.", "slug": "analysis", "order_index": 8, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
800,287
AMR-120-0001
Group Actions on 1-Manifolds — Question 1
Does there exist a lattice in a higher-rank simple Lie group admitting a nontrivial action by orientation-preserving homeomorphisms of the interval ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 1 (#1) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
null
null
null
null
null
800,288
AMR-120-0002
Group Actions on 1-Manifolds — Question 2
Does there exist an infinite, finitely-generated Kazhdan group of circle homeomorphisms ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 2 (#2) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
800,289
AMR-120-0003
Group Actions on 1-Manifolds — Question 3
Does there exist a nontrivial (hence infinite) Kazhdan group of orientation-preserving homeomorphisms of the interval ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 3 (#3) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,290
AMR-120-0004
Group Actions on 1-Manifolds — Question 4
Does there exist an infinite, finitely-generated group that acts on the real line all of whose actions by orientation-preserving homeomorphisms of the line without global fixed points are of type (iii) ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 4 (#4) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
800,291
AMR-120-0005
Group Actions on 1-Manifolds — Question 5
Does there exist a finitely-generated, amenable, left-orderable group having an isolated order inside an infinite space of left orders ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 5 (#5) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,292
AMR-120-0006
Group Actions on 1-Manifolds — Question 6
Does there exist a finitely-generated, left-orderable group for which the conjugacy action on its space of left orders is minimal (that is, all the orbits are dense) ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 6 (#6) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
800,293
AMR-120-0007
Group Actions on 1-Manifolds — Question 7
Does there exist a finitely-generated, left-orderable group without free subgroups and admitting no nontrivial homomorphism into $\mathbb{Z}$ ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 7 (#7) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
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null
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null
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null
null
800,294
AMR-120-0008
Group Actions on 1-Manifolds — Question 8
Does there exist a finitely-generated, left-orderable group $G$ with no nontrivial homomorphism into $\mathbb{Z}$ and trivial group of bounded cohomology $\mathrm{H}^2_b (G, \mathbb{R})$ ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 8 (#8) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
800,295
AMR-120-0009
Group Actions on 1-Manifolds — Question 9
Is the group of orientation-preserving homeomorphisms of the 2-disk that are the identity at the boundary left orderable ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 9 (#9) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
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null
null
null
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null
null
800,296
AMR-120-0010
Group Actions on 1-Manifolds — Question 11
Does the group of piecewise-affine circle homeomorphisms contain distorted elements ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 11 (#10) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
null
800,297
AMR-120-0011
Group Actions on 1-Manifolds — Question 12
What are the groups of piecewise-projective homeomorphisms of the interval/circle that are topologically conjugate to groups of $C^1$ diffeomorphisms ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 12 (#11) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
800,298
AMR-120-0012
Group Actions on 1-Manifolds — Question 13
Given $0 < \alpha < \beta < 1$, does there exist a finitely-generated group of $C^{1+\alpha}$ diffeomorphisms of the circle/interval that does not embed into the group of $C^{1+\beta}$ diffeomorphisms ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 13 (#12) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,299
AMR-120-0013
Group Actions on 1-Manifolds — Question 14
Let $G$ be a finitely-generated group of $C^2$ circle diffeomorphisms. Assume that $G$ admits an exceptional minimal set $\Lambda$. Is the Lebesgue measure of $\Lambda$ equal to zero ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 14 (#13) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,300
AMR-120-0014
Group Actions on 1-Manifolds — Question 17
Let $G$ be a finitely-generated group of $C^2$ circle diffeomorphisms. If the action of $G$ is minimal, is it necessarily ergodic with respect to the Lebesgue measure ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 17 (#16) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,301
AMR-120-0015
Group Actions on 1-Manifolds — Question 18
Let $G$ be a finitely-generated group of $C^2$ orientation-preserving circle diffeomorphisms. Does there exist a non-degenerate probability distribution on $G$ for which the stationary measure is absolutely continuous with respect to the Lebesgue measure ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 18 (#17) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
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2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,302
AMR-120-0016
Group Actions on 1-Manifolds — Question 19
Given a symmetric, finitely-supported, non-degenerate probability distribution on Thompson's group $T$, does the Poisson-Furstenberg boundary of $T$ with respect to it identifies with the circle endowed with the corresponding stationary measure ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 19 (#18) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,303
AMR-120-0017
Group Actions on 1-Manifolds — Question 20
Does there exist a faithful action of $\mathbb{Z}^2$ by $C^{\infty}$ orientation-preserving circle diffeomorphisms that is $C^{\infty}$ structurally stable ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 20 (#19) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,304
AMR-120-0018
Group Actions on 1-Manifolds — Question 21
Given $r \geq 1$, is the subset of $\mathrm{Diff}_+^{r} (\mathrm{S}^1)^2$ consisting of pairs of commuting diffeomorphisms locally connected ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 21 (#20) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,305
AMR-120-0019
Group Actions on 1-Manifolds — Question 22
Given a faithful action $\phi_0$ of a finitely generated group $G$ by $C^{\infty}$ circle diffeomorphisms admitting an exceptional minimal set, does there exist a path $\phi_t$ of faithful actions of $G$ that is continuous in the $C^{\infty}$ topology and starts with $\phi_0 = \phi$ so that each $\phi_t$ admits an exce...
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 22 (#21) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,306
AMR-120-0020
Group Actions on 1-Manifolds — Question 23
Let $G$ be a finitely-generated group of circle homeomorphisms whose action is $C^0$ structurally stable. Suppose that $G$ admits infinitely many non semiconjugate actions on the circle. Does $G$ contain a free subgroup in two generators ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 23 (#22) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,307
AMR-120-0021
Group Actions on 1-Manifolds — Question 24
Let $G$ be a finitely-generated group of $C^1$ circle diffeomorphisms. Suppose that $G$ has no resilient pairs. Given $\varepsilon > 0$, can $G$ be conjugated (by a homeomorphism) into a group of Lipschitz homeomorphisms for which the Lipschitz constants of the generators are all $\leq e^{\varepsilon}$ ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 24 (#23) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,308
AMR-120-0022
Group Actions on 1-Manifolds — Question 25
Let $f$ be a $C^2$ circle diffeomorphism of irrational rotation number $\rho$. Does the set of $C^2$ conjugates of $f$ contain the rotation $R_{\rho}$ in its $C^2$-closure ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 25 (#24) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,309
AMR-120-0023
Group Actions on 1-Manifolds — Question 26
For which values of $r > 1$ there exists $s \geq r$ such that for every $C^s$ circle diffeomorphism $f$ of irrational rotation number $\rho$, the sequence $f^{q_n}$ converges to the identity in the $C^r$ topology, where $(q_n)$ is the sequence of denominators of the rational approximations of $\rho$ ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 26 (#25) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,310
AMR-120-0024
Group Actions on 1-Manifolds — Question 27
Let $f$ be a $C^2$ circle diffeomorphism of irrational rotation number $\rho$. Given $\varepsilon > 0$, let $M_{\varepsilon}$ be the *mapping torus* of $f$ over $\mathrm{S}^1 \times [0,\varepsilon]$, that is, the surface obtained by identifying $(x,0) \sim (f(x), \varepsilon)$. Let $\rho (\varepsilon) \in \mathbb{R} / ...
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 27 (#26) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,311
AMR-120-0025
Group Actions on 1-Manifolds — Question 28
Is the (restriction of the) Godbillon-Vey class invariant under topological conjugacy for groups of $C^2$ diffeomorphisms ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 28 (#27) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,312
AMR-120-0026
Group Actions on 1-Manifolds — Question 29
What are the groups of $C^2$ circle diffeomorphisms acting minimally for which the normalizer inside the group of absolutely continuous homeomorphisms coincides with that inside the group of diffeomorphisms ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 29 (#28) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,313
AMR-120-0027
Group Actions on 1-Manifolds — Question 30
Does Denjoy's theorem hold for circle homeomorphisms whose graphs are real-analytic ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 30 (#29) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,314
AMR-120-0028
Group Actions on 1-Manifolds — Question 31
Is the continuous cohomology of the group $\mathrm{Diff}^{\omega}_+(\mathrm{S}^1)$ of orientation-preserving, real-analytic circle diffeomorphisms generated by the Euler and the Godbillon--Vey classes ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 31 (#30) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
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0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,315
AMR-120-0029
Group Actions on 1-Manifolds — Question 32
Is the group of orientation-preserving $C^2$ circle diffeomorphisms simple ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 32 (#31) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,316
AMR-120-0030
Group Actions on 1-Manifolds — Question 33
Does the Tits alternative hold in $\mathrm{Diff}_+^{\omega} (\mathrm{S}^1)$ ? More precisely, does every non-metabelian subgroup of this group contain a free subgroup ?
Source list: Navas - Group Actions on 1-Manifolds: A List of Very Concrete Open Questions (2017) Source item: Question 33 (#32) Source URL: https://arxiv.org/abs/1712.06462 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Navas
2,017
11
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 11, "name": "dynamical_systems", "display_name": "Dynamical Systems", "description": "Problems about long-term behavior of deterministic systems, Hamiltonian dynamics, and periodic orbits.", "slug": "dynamical-systems", "order_index": 11, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,317
AMR-121-0001
Complexity in Enumerative Combinatorics — Conjecture 1 (Wilf)
Now, for a *combinatorial sequence* $\{a_n\}$ one can ask if there is a Wilfian formula. In the original paper [Wilf] an explicit example is given: Let $a_n$ be the number of unlabeled graphs on $n$ vertices. Then $\{a_n\}$ has no Wilfian formula of type \textup{\small $($\textrm{W1}$)$}.
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Conjecture 1 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex Notes and literature: Attribution/Context: Wilf
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,318
AMR-121-0002
Complexity in Enumerative Combinatorics — Conjecture 2
Let $a_n$ be the number of unlabeled plane triangulations with $n$ vertices, and let $b_n$ be the number of $3$-connected planar graphs with $n$ vertices. Then $\{a_n\}$ and $\{b_n\}$ can be computed in \mathrm{poly}$(n)$ time.
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Conjecture 2 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,319
AMR-121-0003
Complexity in Enumerative Combinatorics — Conjecture 3
It was shown in [Ges] that similar polynomial recurrences exist for the number of $k$-regular labeled graphs, for every fixed $k\ge 1$. Fix $k\ge 1$ and let $a_n$ be the number of unlabeled $k$-regular graphs with $n$ vertices. Then $\{a_n\}$ can be computed in \textup{\textrm{poly}}$(n)$ time.
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Conjecture 3 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,320
AMR-121-0004
Complexity in Enumerative Combinatorics — Conjecture 4
For a fixed ${\text **T** } $, let $g(m,n)$ denote the number of tilings of $[m\times n]$ with ${\text **T** } $. Is $g(m,n)$ computable in polynomial time? The following conjecture suggests otherwise. There exists a finite set of tiles ${\text **T** } $ such that counting the number of tilings of $[n\times n]$ } $ is...
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Conjecture 4 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,321
AMR-121-0005
Complexity in Enumerative Combinatorics — Problem 5 (Pak--Yeliussizov)
This also implies that $y(t)$ is not D-finite. Indeed, observe by definition, that if a sequence $\{a_n\}$ is P-recursive, then so is $\{n! $, which implies the result by taking $a_n=B_n/n!$ (cf. [LR]). Of course, there is a more direct way to prove that $y(t)$ is not $D$-finite by repeated differentiation or via the a...
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Problem 5 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex Notes and literature: Attribution/Context: Pak--Yeliussizov
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,322
AMR-121-0006
Complexity in Enumerative Combinatorics — Conjecture 6
Before we proceed to more combinatorial examples, let us mention that D-transcendental GFs are the subject of *Differential Galois Theory*, which goes back to Liouville, Lie, Picard and Vessiot in the 19th century (see e.g. [Ritt]), and continues to be developed [Put-S]. Some natural GFs are known to be D-transcendenta...
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Conjecture 6 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,323
AMR-121-0007
Complexity in Enumerative Combinatorics — Conjecture 7
Here $p_n$ is the $n$-th prime, and $\pi(n)$ is the number of primes $\le n$, as above. Both GFs are known to be non-D-finite, as shown by Flajolet, Gerhold and Salvy in [FGS] by asymptotic arguments. The authors quip: ``*Almost anything is non-holonomic unless it is holonomic by design*''. Well, maybe so. But the same...
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Conjecture 7 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,324
AMR-121-0008
Complexity in Enumerative Combinatorics — Conjecture 8 (cf. [Zei])
Let $a_n$ denotes the number of self-avoiding walks $O\to O$ in $\mathbb{Z}^2$ of length $n$. Then the sequence $\{a_n\}$ has no Wilfian formula of type \textup{\small $($\textrm{W1}$)$}.
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Conjecture 8 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex Notes and literature: Attribution/Context: cf. [Zei]
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,325
AMR-121-0009
Complexity in Enumerative Combinatorics — Problem 9
In a forthcoming paper [GP-ADE] we construct an explicit but highly artificial non-symmetric set $S\subset F_k\times F_\ell$ In [KP2] we use the tools in [KP1] to prove that groups have an uncountable set of *spectral radii* $$ \rho(G,S) := \lim_{n\to \infty} a_n(G,S)^{1/n} $$ Since the set of D-algebraic sequence is c...
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Problem 9 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,326
AMR-121-0010
Complexity in Enumerative Combinatorics — Problem 10
Can }}_n(1324)\}$ $(n)$ time? (In 2005, Doron Zeilberger expressed doubts that $\text{{\rm \textsf{A}}}_{1000}(1324)$ This sentiment has been roundly criticized on both mathematical and theological grounds (see [Ste]). ) More generally, can one find a single permutation $\pi$ such that }}_n(\pi)\}$ $(n)$ time? Is the c...
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Problem 10 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,327
AMR-121-0011
Complexity in Enumerative Combinatorics — Problem 11
One especially notable case of a combinatorial interpretation is the problem of computing the *Kronecker coefficients* of the symmetric group, which are defined by $$\chi^\lambda \cdot \chi^\mu = \sum_{\nu\vdash n} g(\lambda,\mu,\nu) \. \chi^\nu, \quad \text{where} \ \ \lambda,\mu \vdash n $$ and $\chi^\lambda, of $S_n...
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Problem 11 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,328
AMR-121-0012
Complexity in Enumerative Combinatorics — Problem 12
The original proof is an elegant double counting argument modulo $2$. This suggests the following open problem: (This problem was suggested to us by Peter Shor https://tinyurl.com/y7yafneh (https://cstheory.stackexchange.com/questions/33508).) Find a combinatorial interpretation for $N_e(G)/2$.
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Problem 12 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,329
AMR-121-0013
Complexity in Enumerative Combinatorics — Conjecture 13 (cf. [Ges-sem])
In [Ges-sem], the author defined the following *Gessel sequence*: $$ b_n := \ 2\cdot 5^n \. - \. (3+4i)^{n} \. - \. (3-4i)^{n}, \quad \text{where} \ \ i \. = \. \sqrt{-1} $$ see also [OEIS, A250102 (https://oeis.org/A250102)]. Note that $b_n\in \mathbb{Z}$ since $$b_n = 2\cdot 5^n \. - \. 2 {2r} \. 3^{n-2r} $$ and that...
Source list: Pak - Complexity Problems in Enumerative Combinatorics (2018) Source item: Conjecture 13 Source URL: https://arxiv.org/abs/1803.06636 Accessed: 2026-10-16 Extraction: arxiv_latex Notes and literature: Attribution/Context: cf. [Ges-sem]
3
open
Pak
2,018
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,330
AMR-122-0001
Enumeration of Matchings — Problem 1
Show that in the $2n-1,2n,2n-1$ semiregular hexagon, the central location (consisting of the two innermost triangles) is covered by a lozenge in exactly one-third of the tilings. (Equivalently: Show that if one chooses a random perfect matching of the dual graph, the probability that the central edge is contained in t...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 1 (#1) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,331
AMR-122-0002
Enumeration of Matchings — Problem 2
\end{verbatim} These are similar to the numbers one gets from counting lozenge-tilings of an $n,n,n,n,n,n$ hexagon, in that the largest prime factor seems to be bounded by a linear function of $n$, and it ought to be possible to come up with a conjectural exact formula. What might be harder is proving it. Enumerate th...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 2 (#2) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
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Propp
1,998
2
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{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,332
AMR-122-0003
Enumeration of Matchings — Problem 3
10 3 8 2 4 2 (2) (3) (5) (13) (17) (19) 2 2 2 3 4 4 8 4 (2) (5) (7) (11) (13) (17) (19) (23) \end{verbatim} Enumerate the lozenge-tilings of the region obtained from the $2n,2n+3,2n,2n+3,2n,2n+3$ hexagon by removing a triangle from the middle of each of its long sides.
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 3 (#3) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
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0
2026-10-16T14:00:00
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true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,333
AMR-122-0004
Enumeration of Matchings — Problem 4
Determine the number of lozenge-tilings of a regular hexagon from which two of its innermost unit triangles (one upward-pointing and one downward-pointing) have been removed.
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 4 (#4) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,334
AMR-122-0005
Enumeration of Matchings — Problem 5
Determine the cokernel of the Carlitz matrices, or equivalently of the Kasteleyn matrices of $a,b,c$ hexagons, and if possible find a way to interpret the cokernel in terms of the tilings. He points out that in the case $a=b=c=2$, one gets a non-cyclic group as the cokernel.
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 5 (#5) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,335
AMR-122-0006
Enumeration of Matchings — Problem 6
Digressing for a moment from the topic of lozenge tilings, I point out that in general, the Kasteleyn matrix $K$ is not canonically defined, in the sense that there may be many ways of modifying the signs of certain entries of the bipartite adjacency matrix of a graph so that all non-zero contributions to the determina...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 6 (#6) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,336
AMR-122-0007
Enumeration of Matchings — Problem 7
Find the ``vertical moments of inertia'' for the mass on edges arising from edge-probabilities for random matchings of the $a,b,c$ honeycomb graph.
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 7 (#7) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,337
AMR-122-0008
Enumeration of Matchings — Problem 8
47 2 (2) (3) (5) \end{verbatim} Note that only the presence of the large prime factor 73 makes one doubt that there is a general formula; the other prime factors are reassuringly small. Further data might make it clear what that 73 is doing there. Count the domino tilings of an Aztec diamond from which two close-to-ce...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 8 (#8) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
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true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,338
AMR-122-0009
Enumeration of Matchings — Problem 9
One can also look at ``Aztec rectangles'' from which squares have been removed so as to restore the balance between black and white squares (a necessary condition for tilability). For instance, one can remove the central square from an $a$-by-$b$ Aztec rectangle in which $a$ and $b$ differ by 1, with the larger of $a,b...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 9 (#9) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
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2026-10-16T14:00:00
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{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,339
AMR-122-0010
Enumeration of Matchings — Problem 10
What about $(2n-1)$-by-$2n$ rectangles? For these regions, removing the central square does not make the region tilable. However, if one removes any one of the four squares adjacent to the middle square, one obtains a region that is tilable, and moreover, for this region the number of tilings appears to be a nice round...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 10 (#10) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
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0
2026-10-16T14:00:00
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true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,340
AMR-122-0011
Enumeration of Matchings — Problem 11
Perhaps this is a special case of a two-parameter fact that says that you can take an intrusion of length $m$ in a $2n$-by-$2n$ square and the number of tilings of the resulting region will always be a square or twice a square. What is going on with ``intruded Aztec diamonds''? In particular, why is the number of tili...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 11 (#11) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
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2026-10-16T14:00:00
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true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,341
AMR-122-0012
Enumeration of Matchings — Problem 12
Consider the Kasteleyn matrix $K_n$ for the Aztec diamond of order $n$, in which every other vertical domino has its sign flipped (that is, the corresponding 1's in the bipartite adjacency matrix are replaced by $-1$'s). Show that the sum of the entries of the matrix inverse of $K_n$ is $(n-1)(n+3)/2 - 2^{n-1} + 2$. ...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 12 (#12) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
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2026-10-16T14:00:00
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{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,342
AMR-122-0013
Enumeration of Matchings — Problem 13
Find a general formula for the number of domino tilings of even pillows.
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 13 (#13) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
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2026-10-16T14:00:00
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{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,343
AMR-122-0014
Enumeration of Matchings — Problem 14
Find a general formula for the number of domino tilings of Aztec windows. Even an argument explaining why the number of tilings for windows of inner order $x$ and outer order $x+w$ should be given by a polynomial in $x$ (for each fixed $w$) would constitute progress!
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 14 (#14) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,344
AMR-122-0015
Enumeration of Matchings — Problem 15
One case that has not yet been settled is the case that arises from a rather symmetric dissection of the plane into equilateral triangles, squares, and regular hexagons, with 4 polygons meeting at each vertex. Empirically, one finds that the number of diform tilings is $2^{n(n+1)}$. Prove that for the Aztec-type regio...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 15 (#15) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,345
AMR-122-0016
Enumeration of Matchings — Problem 16
For instance, we have the roughly hexagonal region shown at the top of the next page (a union of square and triangular pieces, with certain boundary vertices marked with a ``.''\ so as to bring out the large-scale 2,3,2,2,3,2 hexagonal structure more clearly); it has 17920 tilings, where 17920 is $2^9 \cdot 5 \cdot 7$....
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 16 (#16) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,346
AMR-122-0017
Enumeration of Matchings — Problem 17
Characterize those local substitutions that have a predictable effect on the weighted sum of matchings of a graph. The most useful local substitution so far has been \begin{verbatim} q q | C / \ D a u b / \ / \ / \ p---t v---r ----> p r \ / \ / d w c \ / | B \ / A s s \end{verbatim} (where unmarked edges have weight ...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 17 (#17) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
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null
800,347
AMR-122-0018
Enumeration of Matchings — Problem 18
How many perfect matchings does the triangle graph of order $n$ have?
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 18 (#18) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
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null
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800,348
AMR-122-0019
Enumeration of Matchings — Problem 19
One can also look at graphs that are bipartite but not planar. A natural example is the $n$-cube (that is, the $n$-dimensional cube with all sides of length 2). It has been shown that the number of perfect matchings of the $n$-cube goes like $1$, $2$, $9=3^2$, $272=16 \cdot 17$, $589185=3^2 \cdot 5 \cdot 13093$, $\dots...
Source list: Propp - Twenty Open Problems in Enumeration of Matchings (1998) Source item: Problem 19 (#19) Source URL: https://arxiv.org/abs/math/9801060 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
1,998
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
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800,349
AMR-123-0001
Trimer Covers in the Triangular Grid — Problem 1
Find an exact formula for $T_{003}(k(3k-1)/2,k(3k+1)/2)$. Of course, even short of an exact formula, any method of determining the number of tilings that is more efficient than brute-force enumeration (e.g., a recurrence relation) would be of interest. See [KiPr] for more discussion of no-stones tilings of benzels.
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 1 (#1) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
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null
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null
800,350
AMR-123-0002
Trimer Covers in the Triangular Grid — Problem 4
When $a$ and $b$ are such that the Conway-Lagarias invariant is strictly positive, the $(a,b)$-benzel cannot be tiled by bones and left stones; the corresponding entries in the table must be zero. On the other hand, when $a$ and $b$ are such that the Conway-Lagarias invariant is negative or zero, the entries in the tab...
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 4 (#2) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
null
null
null
null
null
null
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800,351
AMR-123-0003
Trimer Covers in the Triangular Grid — Problem 7
In parallel with the observations that preceded Problem 4, note that when the Conway-Lagarias invariant of a benzel is strictly negative, the benzel cannot be tiled by bones and right-pointing stones; the corresponding entries in the table must be zero. On the other hand, when $a$ and $b$ are such that the Conway-Lagar...
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 7 (#3) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
null
null
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null
null
null
null
null
null
null
null
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null
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null
800,352
AMR-123-0004
Trimer Covers in the Triangular Grid — Problem 11
With $T(n) = T_{112}(3n-1,3n)$ with $n \geq 1$, it appears that $T(n)$ has no prime factor greater than or equal to $4n$. Find a formula governing $T_{112}(3n-1,3n)$. See OEIS entry A364483 (https://oeis.org/A364483). We now switch from central diagonals to peripheral diagonals.
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 11 (#4) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
null
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null
null
null
null
null
null
null
null
null
null
null
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null
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null
800,353
AMR-123-0005
Trimer Covers in the Triangular Grid — Problem 12
Is it true that $T_{112}(n+2,2n+1)$ is the ``$n$th large Schr\"oder number'' (see OEIS entry A006318 (https://oeis.org/A006318)) for all $n \geq 1$? Equality has been verified for $1 \leq n \leq 15$.
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 12 (#5) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
null
null
null
null
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null
null
null
null
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null
null
null
800,354
AMR-123-0006
Trimer Covers in the Triangular Grid — Problem 13
Is it true that $T_{112}(n+2,2n)$ is the number of ``royal paths in a lattice of order $n$'' (see OEIS entry A006319 (https://oeis.org/A006319)) for all $n \geq 1$? Equality has been verified for $1 \leq n \leq 15$.
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 13 (#6) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
null
null
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null
null
null
null
null
null
null
null
null
null
null
null
null
null
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null
null
800,355
AMR-123-0007
Trimer Covers in the Triangular Grid — Problem 15
Is $T_{113}(n,2n-4)$ 2-adically continuous as a function of $n \geq 5$? Comment: The sequence appears to be constant mod 2, constant mod 4, 2-periodic mod 8, and 8-periodic mod 16 (with repeating pattern 4, 4, 4, 4, 4, 12, 4, 12). The case $n = 4$ breaks the pattern. See OEIS entry A364416 (https://oeis.org/A364416).
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 15 (#7) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
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null
null
null
null
null
null
null
null
null
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null
null
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null
800,356
AMR-123-0008
Trimer Covers in the Triangular Grid — Problem 16
Is $T_{113}(n,2n-3)$ 2-adically continuous as a function of $n \geq 4$? Comment: The sequence appears to be constant mod 2, constant mod 4, 2-periodic mod 8, and 8-periodic mod 16 (with repeating pattern 2, 14, 2, 14, 10, 6, 10, 6). The case $n = 3$ breaks the pattern. See OEIS entry A364417 (https://oeis.org/A364417)...
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 16 (#8) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
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null
null
null
null
null
null
null
null
null
null
null
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null
null
null
null
null
null
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null
800,357
AMR-123-0009
Trimer Covers in the Triangular Grid — Problem 17
Is $T_{113}(n,2n-4;3)$ 2-adically continuous as a function of $n \geq 5$? Comment: The sequence appears to be constant mod 2, constant mod 4, constant mod 8, and 8-periodic mod 16 (with repeating pattern 4, 4, 12, 12, 4, 12, 12, 4). The case $n = 4$ breaks the pattern. See OEIS entry A364418 (https://oeis.org/A364418)...
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 17 (#9) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
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null
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null
null
null
null
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null
null
800,358
AMR-123-0010
Trimer Covers in the Triangular Grid — Problem 18
Comment: The sequence appears to be constant mod 2, constant mod 4, constant mod 8, and 8-periodic mod 16 (with repeating pattern 4, 4, 12, 12, 4, 12, 12, 4). The case $n = 4$ breaks the pattern. See OEIS entry A364418 (https://oeis.org/A364418). Is $T_{113}(n,2n-3;3)$ 2-adically continuous as a function of $n \geq 4$...
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 18 (#10) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
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null
null
null
null
null
null
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null
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null
800,359
AMR-123-0011
Trimer Covers in the Triangular Grid — Problem 20
The question we ask is, how many such tiling are there? OEIS entry A334875 (https://oeis.org/A334875) gives the answers for small values of $n$. If we look at the prime factorizations of the answers, we notice that the exponent of the prime 2 is creeping upward. Specifically, the multiplicity of the prime 2 in the fact...
Source list: Propp - Trimer Covers in the Triangular Grid: Twenty Mostly Open Problems (2022) Source item: Problem 20 (#11) Source URL: https://arxiv.org/abs/2206.06472 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Propp
2,022
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
800,360
AMR-124-0001
Iwahori-Hecke Algebras — Problem 1
Let $I$ be a finite set and let $(m_{ij})_{(i,j)\in I\times I}$ be a symmetric matrix whose diagonal entries are $1$ and whose nondiagonal entries are integers $\ge2$ or $\infty$. Let $W$ be the group with generators $\{s_i;i\in I\}$ and relations $(s_is_j)^{m_{ij}}=1$ for any $i,j$ such that $m_{ij}<\infty$; this is a...
Source list: Lusztig - Open Problems on Iwahori-Hecke Algebras (2020) Source item: Problem 1 Source URL: https://arxiv.org/abs/2006.08535 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Lusztig
2,020
4
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 4, "name": "algebra", "display_name": "Algebra", "description": "Group theory, ring theory, field theory, and algebraic structures.", "slug": "algebra", "order_index": 4, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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null
null
null
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null
null
null
null
null
null
null
null
null
null
null
null
null
null
null
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null
null
null
null
800,361
AMR-124-0002
Iwahori-Hecke Algebras — Problem 2
There is a unique group homomorphism $\bar{}:H@>>>H$ such that $\overline{v^nT_w}T_{w\i}=v^{-n}$ for $n\in\mathbb{Z},w\in W$; it is a ring isomorphism. Let $H_{\le0}=\sum_{w\in W}\mathbb{Z}[v - ]T_w\subset H$. For any $w\in W$ there is a unique element $c_w\in H_{\le0}$ such that $\bar c_w=c_w$ and $c_w-T_w\in v - H_{\...
Source list: Lusztig - Open Problems on Iwahori-Hecke Algebras (2020) Source item: Problem 2 Source URL: https://arxiv.org/abs/2006.08535 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Lusztig
2,020
4
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 4, "name": "algebra", "display_name": "Algebra", "description": "Group theory, ring theory, field theory, and algebraic structures.", "slug": "algebra", "order_index": 4, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,362
AMR-124-0003
Iwahori-Hecke Algebras — Problem 3
Assume that $W$ is finite and that $L=||$. Let $C$ be a conjugacy class in $W$; let $C_{min}$ be the set of all $w\in C$ such that $|w|$ is minimal. For $w\in C$ let $N^w\in A$ be the trace of the $A$-linear map $H@>>>H$, $h\mapsto v^{2|w|}T_whT_{w\i}$. We have $N^w\in\mathbb{Z}[v^2]$. (Note that $N^w|_{v=1}$ is the or...
Source list: Lusztig - Open Problems on Iwahori-Hecke Algebras (2020) Source item: Problem 3 Source URL: https://arxiv.org/abs/2006.08535 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Lusztig
2,020
4
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 4, "name": "algebra", "display_name": "Algebra", "description": "Group theory, ring theory, field theory, and algebraic structures.", "slug": "algebra", "order_index": 4, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,363
AMR-125-0001
Coxeter Groups and Unimodality — Problem 1
It is well known (see, e.g., [Hum, Prop. 5.12] or [BB, Cor. 7.1.4]) that if $(W,S)$ is a Coxeter system then $\sum_{u \in W} x^{\ell(u)}$ is a rational generating function. The following problem was proposed by Stembridge in [Ste97]. Let $(W,S)$ be a Coxeter system. Is it true that then \[ \sum_{t \in T} x^{\ell(t)} \...
Source list: Brenti - Some Open Problems on Coxeter Groups and Unimodality (2024) Source item: Problem 1 Source URL: https://arxiv.org/abs/2410.09897 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Brenti
2,024
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,364
AMR-125-0002
Coxeter Groups and Unimodality — Conjecture 2
Let $(W_1,S_1)$, $(W_2,S_2)$ be two Coxeter systems, and $u,v \in W_1$, $w,z \in W_2$ be such that $[u,v] \simeq [w,z]$ (isomorphic as posets). Then \begin{equation} P_{u,v}(q)=P_{w,z}(q). \end{equation}
Source list: Brenti - Some Open Problems on Coxeter Groups and Unimodality (2024) Source item: Conjecture 2 Source URL: https://arxiv.org/abs/2410.09897 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Brenti
2,024
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,365
AMR-125-0003
Coxeter Groups and Unimodality — Conjecture 3
Let $(W_1,S_1)$, $(W_2,S_2)$ be two Coxeter systems, $J_1 \subseteq S_1$, $J_2 \subseteq S_2$, $u,v \in W_1^{J_1}$, $w,z \in W_2^{J_2}$ and $f: [u,v] \rightarrow [w,z]$ be a poset isomorphism such that $f([u,v]^{J_1})=[w,z]^{J_2}$. Then \begin{equation} P_{u,v}^{J_1,q}(q)=P_{w,z}^{J_2,q}(q). \end{equation}
Source list: Brenti - Some Open Problems on Coxeter Groups and Unimodality (2024) Source item: Conjecture 3 Source URL: https://arxiv.org/abs/2410.09897 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Brenti
2,024
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,366
AMR-125-0004
Coxeter Groups and Unimodality — Conjecture 4
Let $W$ be a Weyl group of type $A$ and $u,v \in W$, $u \leq v$. Then \begin{equation} P_{u,v}(q) = \widetilde{P}_{u,v,z}(q) \end{equation} for any hypercube decomposition $[u,z]$ of $[u,v]$.
Source list: Brenti - Some Open Problems on Coxeter Groups and Unimodality (2024) Source item: Conjecture 4 Source URL: https://arxiv.org/abs/2410.09897 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Brenti
2,024
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,367
AMR-125-0005
Coxeter Groups and Unimodality — Conjecture 5
Let $(W,S)$ be a Coxeter system, and $u,v \in W$, $u \leq v$. Then \[ \widetilde{\Phi}_{u,v} \in \mathbb{N} \langle c,d \rangle. \]
Source list: Brenti - Some Open Problems on Coxeter Groups and Unimodality (2024) Source item: Conjecture 5 Source URL: https://arxiv.org/abs/2410.09897 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Brenti
2,024
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,368
AMR-125-0006
Coxeter Groups and Unimodality — Problem 6
It is known ([Polo], see also [CasRep]) that if $P(q) \in \mathbb{N}[q]$ is such that $P(0)=1$ then there are $n \in \mathbb{P}$ and $u,v \in S_n$ such that $P(q)=P_{u,v}(q)$. The following related problem was posed by Bj\"{o}rner ([BjoPC]). Let $(W,S)$ be a Coxeter system and $u,v \in W$, $u \leq v$. Is it true that ...
Source list: Brenti - Some Open Problems on Coxeter Groups and Unimodality (2024) Source item: Problem 6 Source URL: https://arxiv.org/abs/2410.09897 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Brenti
2,024
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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800,369
AMR-125-0007
Coxeter Groups and Unimodality — Problem 7
The proof of the celebrated nonnegativity conjecture for Kazhdan-Lusztig polynomials ([EW]) makes the following problem even more compelling. Find a combinatorial interpretation for Kazhdan-Lusztig polynomials.
Source list: Brenti - Some Open Problems on Coxeter Groups and Unimodality (2024) Source item: Problem 7 Source URL: https://arxiv.org/abs/2410.09897 Accessed: 2026-10-16 Extraction: arxiv_latex
3
open
Brenti
2,024
2
13
0
0
2026-10-16T14:00:00
2026-10-16T14:00:00
true
{ "id": 2, "name": "combinatorics", "display_name": "Combinatorics", "description": "Counting problems, graph theory, discrete structures.", "slug": "combinatorics", "order_index": 2, "created_at": "2026-07-31T15:26:25.671Z" }
{ "id": 3, "level": 3, "name": "L3: Advanced", "description": "Difficult problems requiring specialized knowledge and sophisticated techniques.", "color_class": "text-yellow-600 bg-yellow-50 border-yellow-200" }
{ "id": 13, "name": "amr_open_problem_lists", "display_name": "AMR Open Problem Lists", "description": "Open and partially solved problems collected from public source lists indexed by AMR, with per-record provenance and status notes.", "slug": "amr-open-problem-lists", "order_index": 13, "created_at": "2...
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