OAI/Geometry/RCD/Sobolev/BoundedLpSquare.lean
4 declarations, 0 contain sorry, 0 declared as axioms
L² continuity of squares on uniformly bounded sets
The heat-variance differentiation needs the square to remain in L² while the underlying bounded heat path varies in L².
- def
OAI.RegularPointCoordinates.boundedLpSquareline 20Source documentation
The square of a bounded L² function is again an actual L² function.
def boundedLpSquare (f : Lp ℝ 2 μ) (C : ℝ) (_hC : 0 ≤ C) (hf : ∀ᵐ x ∂μ, |f x| ≤ C) : Lp ℝ 2 μ := … - theorem
OAI.RegularPointCoordinates.boundedLpSquare_coeline 31 - theorem
OAI.RegularPointCoordinates.boundedLpSquare_sub_norm_leline 39Source documentation
A quantitative continuity estimate requiring only L² distance and separate bounds on the two functions.
theorem boundedLpSquare_sub_norm_le (f g : Lp ℝ 2 μ) (C D : ℝ) (hC : 0 ≤ C) (hD : 0 ≤ D) (hf : ∀ᵐ x ∂μ, |f x| ≤ C) (hg : ∀ᵐ x ∂μ, |g x| ≤ D) : ‖boundedLpSquare μ f C hC hf-boundedLpSquare μ g D hD hg‖ ≤ (C+D)*‖f-g‖ := by … - theorem
OAI.RegularPointCoordinates.boundedLpSquare_continuousAtline 58Source documentation
Uniform boundedness makes squaring continuous along an L² path.
theorem boundedLpSquare_continuousAt {F : ℝ → Lp ℝ 2 μ} {t C : ℝ} (hC : 0 ≤ C) (hF : ContinuousAt F t) (hb : ∀ s, ∀ᵐ x ∂μ, |F s x| ≤ C) : ContinuousAt (fun s => boundedLpSquare μ (F s) C hC (hb s)) t := by …