OAI/GroupTheory/Thompson/Main.lean
5 declarations, 0 contain sorry, 0 declared as axioms
- theorem
OAI.ThompsonNonamenability.thompson_F_boundary_with_exact_constantline 16 - theorem
OAI.ThompsonNonamenability.thompson_F_boundary_constant_formulaline 38Source documentation
The displayed formula has no additional normalization or hidden factor.
theorem thompson_F_boundary_constant_formula (D : ℕ) : boundaryConstant Analytic.displacementLipschitzConstant (1 / 2) D = ((1 / 2 : ℝ) ^ 2 / Analytic.displacementLipschitzConstant ^ 2 - 4 / (D : ℝ)) / (4 * (1 - 1 / (D : ℝ))) := rflMentions: OAI.ThompsonNonamenability.boundaryConstant, OAI.ThompsonNonamenability.Analytic.displacementLipschitzConstant
- theorem
OAI.ThompsonNonamenability.thompson_F_uniform_boundaryline 45Source documentation
A fixed finite subset of the genuine PL group uniformly expands every nonempty finite subset, in the unnormalized symmetric-difference form.
theorem thompson_F_uniform_boundary : ∃ (S : Finset F) (b : ℝ), S.Nonempty ∧ 0 < b ∧ ∀ A : Finset F, A.Nonempty → ∃ h ∈ S, b * (A.card : ℝ) ≤ ((leftTranslate h A ∆ A).card : ℝ) := by …Mentions: OAI.ThompsonNonamenability.F, OAI.ThompsonNonamenability.leftTranslate
- theorem
OAI.ThompsonNonamenability.thompson_F_not_amenableline 65Source documentation
Standard Thompson F admits no positive normalized left-invariant mean on all bounded real functions. The carrier is identified with the ordinary finite-breakpoint dyadic PL homeomorphisms by
F.standardPLEquiv.theorem thompson_F_not_amenable : ¬ Nonempty (InvariantMean F) := by …
Mentions: OAI.ThompsonNonamenability.InvariantMean, OAI.ThompsonNonamenability.F
- theorem
OAI.ThompsonNonamenability.thompson_F_nonamenable_compositionline 69Distinct definitions of this name: ComparatorChallenges/ThompsonNonamenability.lean:78 (same statement text; different proof or body). Qualify references as OAI.ThompsonNonamenability.thompson_F_nonamenable_composition@path.