OAI/GroupTheory/PolycyclicRecognition/Algebra/ConditionalGroupRecognition.lean

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2 declarations, 0 contain sorry, 0 declared as axioms

The metric-free group formulation of conditional recognition

For finitely generated groups, GroupCoarseEquivalence expresses the finite-difference control of quasi-isometry in word metrics. The proof constructs the finite word metrics and their linear chains explicitly.

  1. theorem OAI.PolycyclicRecognition.group_recognition_of_published_inputs line 18

    Source documentation

    Recognition of a finitely generated group coarsely equivalent to a virtually polycyclic group, with no auxiliary metric assumptions.

    theorem group_recognition_of_published_inputs
        (inputs : PublishedRecognitionInputs)
        {P J : Type} [Group P] [Group J] [Group.FG P] [Group.FG J]
        (e : GroupCoarseEquivalence P J) (hP : IsVirtuallyPolycyclic P) :
        IsVirtuallyPolycyclic J ∧
          ∃ Γ : Subgroup J, Γ.FiniteIndex ∧
            ∃ (S : SimplyConnectedSolvableLieModel) (Λ : Subgroup S.carrier),
              IsUniformLattice Λ ∧ Nonempty (Γ ≃* Λ) := by
    …

    Mentions: OAI.PolycyclicRecognition.PublishedRecognitionInputs, OAI.PolycyclicRecognition.GroupCoarseEquivalence, OAI.PolycyclicRecognition.SimplyConnectedSolvableLieModel

  2. theorem OAI.PolycyclicRecognition.uniform_lattice_recognition_of_published_inputs line 47

    Source documentation

    In particular a group quasi-isometric to a uniform solvable Lie lattice has a finite-index subgroup which is a uniform solvable Lie lattice.

    theorem uniform_lattice_recognition_of_published_inputs
        (inputs : PublishedRecognitionInputs)
        (S : SimplyConnectedSolvableLieModel) (Λ : Subgroup S.carrier)
        (hΛ : IsUniformLattice Λ)
        {J : Type} [Group J] [Group.FG J] (e : GroupCoarseEquivalence Λ J) :
        ∃ Γ : Subgroup J, Γ.FiniteIndex ∧
          ∃ (R : SimplyConnectedSolvableLieModel) (Δ : Subgroup R.carrier),
            IsUniformLattice Δ ∧ Nonempty (Γ ≃* Δ) := by
    …

    Mentions: OAI.PolycyclicRecognition.PublishedRecognitionInputs, OAI.PolycyclicRecognition.SimplyConnectedSolvableLieModel, OAI.PolycyclicRecognition.GroupCoarseEquivalence