openAI-math-dataset / lean /OAI /Geometry /SingularHomology /HomologySpectrumFactor.lean
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import OAI.Dynamics.EntropyCounterexample.PolynomialSpectralBound
import OAI.Geometry.SingularHomology.HomologyTransfer
import OAI.Dynamics.EntropyCounterexample.FiniteSpectrumBound
namespace OAI
noncomputable section
namespace Problem340
open PolynomialSpectrum
variable {X Y : Type} [TopologicalSpace X] [TopologicalSpace Y]
theorem homology_pairRadii_factor_subset (n : ℕ)
(f : X → X) (i : Y → X) (p : X → Y)
(hf : Continuous f) (hi : Continuous i) (hp : Continuous p)
(H : ContinuousMap.Homotopy (continuousMapOf f hf)
(continuousMapOf (i ∘ p) (hi.comp hp))) :
pairRadii (realHomologyMap n f hf) ⊆
insert 0 (pairRadii (realHomologyMap n (p ∘ i) (hp.comp hi))) := by
rw [realHomologyMap_eq_of_homotopy n hf (hi.comp hp) H,
realHomologyMap_comp n p i hp hi, realHomologyMap_comp n i p hi hp]
exact pairRadii_comp_subset _ _
theorem bddAbove_homology_pairRadii_of_homotopy_factor
(f : X → X) (i : Y → X) (p : X → Y)
(hf : Continuous f) (hi : Continuous i) (hp : Continuous p)
(H : ContinuousMap.Homotopy (continuousMapOf f hf)
(continuousMapOf (i ∘ p) (hi.comp hp)))
(hB : BddAbove (⋃ n, pairRadii (realHomologyMap n (p ∘ i) (hp.comp hi)))) :
BddAbove (⋃ n, pairRadii (realHomologyMap n f hf)) := by
apply (hB.insert 0).mono
intro r hr
obtain ⟨n, hn⟩ := Set.mem_iUnion.mp hr
rcases homology_pairRadii_factor_subset n f i p hf hi hp H hn with h | h
· exact Set.mem_insert_iff.mpr (Or.inl h)
· exact Set.mem_insert_of_mem _ (Set.mem_iUnion.mpr ⟨n, h⟩)
theorem bddAbove_homology_pairRadii_of_finite_homotopy_factor
(f : X → X) (i : Y → X) (p : X → Y)
(hf : Continuous f) (hi : Continuous i) (hp : Continuous p)
(H : ContinuousMap.Homotopy (continuousMapOf f hf)
(continuousMapOf (i ∘ p) (hi.comp hp)))
[∀ n, FiniteDimensional ℝ (RealSingularHomology n Y)]
(N : ℕ) (hvanish : ∀ n, N < n → Subsingleton (RealSingularHomology n Y)) :
BddAbove (⋃ n, pairRadii (realHomologyMap n f hf)) := by
apply bddAbove_homology_pairRadii_of_homotopy_factor f i p hf hi hp H
have h := bddAbove_total_pairedEigenvalue_moduli
(fun n => realHomologyMap n (p ∘ i) (hp.comp hi)) N hvanish
simpa only [pairRadii, Set.iUnion_ofPred] using h
theorem totalRealHomologySpectralRadius_eq_sSup_pairRadii
(f : X → X) (hf : Continuous f) :
totalRealHomologySpectralRadius f hf =
sSup (⋃ n, pairRadii (realHomologyMap n f hf)) := by
simp only [totalRealHomologySpectralRadius, pairRadii, Set.iUnion_ofPred]
end Problem340
end
end OAI