OAI/Geometry/RCD/Metric/FiniteCoverIntegral.lean
2 declarations, 0 contain sorry, 0 declared as axioms
Integrating finite covers with bounded overlap
- theorem
OAI.RegularPointCoordinates.integral_le_sum_coverline 17Source documentation
Integrate a nonnegative function over a finite cover, allowing overlap.
theorem integral_le_sum_cover (s : Finset I) (A : I → Set X) (hA : ∀ i ∈ s, MeasurableSet (A i)) {Ω : Set X} (hΩ : MeasurableSet Ω) (hcover : Ω ⊆ ⋃ i ∈ s, A i) {f : X → ℝ} (hf : Integrable f μ) (hpos : ∀ x, 0 ≤ f x) : (∫ x in Ω, f x ∂μ) ≤ ∑ i ∈ s, ∫ x in A i, f x ∂μ := by … - theorem
OAI.RegularPointCoordinates.sum_integral_le_overlapline 42Source documentation
A bound on overlap controls the sum of local integrals by the global integral, with precisely the same multiplicity constant.
theorem sum_integral_le_overlap (s : Finset I) (A : I → Set X) (hA : ∀ i ∈ s, MeasurableSet (A i)) (N : ℕ) (hoverlap : ∀ x, (s.filter (fun i => x ∈ A i)).card ≤ N) {f : X → ℝ} (hf : Integrable f μ) (hpos : ∀ x, 0 ≤ f x) : (∑ i ∈ s, ∫ x in A i, f x ∂μ) ≤ N * ∫ x, f x ∂μ := by …