OAI/GroupTheory/PolycyclicRecognition/Lattices/UniformLatticeQuotient.lean

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3 declarations, 0 contain sorry, 0 declared as axioms

Compact quotient and compact fundamental cover

The concrete uniform lattice definition agrees with the usual compact-coset- quotient definition. Left and right cosets are interchanged by inversion.

  1. theorem OAI.PolycyclicRecognition.IsUniformLattice.compactSpace_quotient line 23

    Source documentation

    The compact fundamental cover gives compactness of the ordinary right coset quotient, without any normality assumption.

    theorem IsUniformLattice.compactSpace_quotient {Λ : Subgroup G}
        (hΛ : IsUniformLattice Λ) : CompactSpace (G ⧸ Λ) := by
    …
  2. theorem OAI.PolycyclicRecognition.isUniformLattice_of_compact_quotient line 48

    Source documentation

    In a locally compact group, a compact coset quotient admits a compact fundamental cover. The finite subcover consists of images of relatively compact neighborhoods.

    theorem isUniformLattice_of_compact_quotient [LocallyCompactSpace G]
        (Λ : Subgroup G) [DiscreteTopology Λ] [CompactSpace (G ⧸ Λ)] :
        IsUniformLattice Λ := by
    …
  3. theorem OAI.PolycyclicRecognition.isUniformLattice_iff_compact_quotient line 73

    Source documentation

    This is the usual uniform-lattice predicate in locally compact groups.

    theorem isUniformLattice_iff_compact_quotient [LocallyCompactSpace G] (Λ : Subgroup G) :
        IsUniformLattice Λ ↔ DiscreteTopology Λ ∧ CompactSpace (G ⧸ Λ) := by
    …