OAI/Topology/CoarseAssembly/SeparatedGeometry.lean
5 declarations, 0 contain sorry, 0 declared as axioms
Bounded geometry of the separated union
Uniform component ball bounds pass to the union. All cross-component pairs in a fixed distance range lie in a finite prefix, which also supplies the finite exceptional set in the transfer argument.
- def
OAI.CoarseAssembly.componentPrefixline 20 - theorem
OAI.CoarseAssembly.mem_componentPrefixline 24 - theorem
OAI.CoarseAssembly.finite_cross_pairsline 30 - theorem
OAI.CoarseAssembly.separated_uniform_finite_ballsline 42Source documentation
The bounded-geometry hypothesis needed by the Roe transfer is preserved by this separated union.
theorem separated_uniform_finite_balls (o : ∀ i, V i) (hcomp : ∀ R : ℝ, 0 ≤ R → ∃ N : ℕ, ∀ i (x : V i), ∃ b : Finset (V i), (∀ y, y ∈ b ↔ dist x y ≤ R) ∧ b.card ≤ N) : @UniformFiniteBalls (Sigma V) (separatedMetric o).toPseudoMetricSpace := by …Mentions: OAI.CoarseAssembly.UniformFiniteBalls, OAI.CoarseAssembly.separatedMetric
- theorem
OAI.CoarseAssembly.separated_uniform_discreteline 80Source documentation
Unit separation in each component gives unit separation in the union.
theorem separated_uniform_discrete (o : ∀ i, V i) (hcomp : ∀ i (x y : V i), x ≠ y → 1 ≤ dist x y) (x y : Sigma V) (hxy : x ≠ y) : 1 ≤ separatedDist o x y := by …Mentions: OAI.CoarseAssembly.separatedDist