OAI/GroupTheory/PolycyclicRecognition/Lattices/UniformLatticeQuotient.lean
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.
- theorem
OAI.PolycyclicRecognition.IsUniformLattice.compactSpace_quotientline 23Source 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 … - theorem
OAI.PolycyclicRecognition.isUniformLattice_of_compact_quotientline 48Source 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 … - theorem
OAI.PolycyclicRecognition.isUniformLattice_iff_compact_quotientline 73Source 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 …