OAI/GroupTheory/Thompson/AnalyticLpCalculus.lean
4 declarations, 0 contain sorry, 0 declared as axioms
Uniform estimates in the concrete Hilbert space
The restricted Lebesgue measure has mass one. Consequently, an almost-everywhere
uniform bound on a representative gives the same bound on its L² norm.
The derivative criterion below turns a quadratic norm remainder into a genuine
derivative in any real normed space, including this Hilbert space.
- theorem
OAI.ThompsonNonamenability.Analytic.intervalMeasure_univline 24 - theorem
OAI.ThompsonNonamenability.Analytic.norm_le_of_ae_boundline 28Source documentation
A uniform bound on an almost-everywhere representative bounds the Hilbert norm.
theorem norm_le_of_ae_bound (f : Hilbert) {C : ℝ} (hC : 0 ≤ C) (hbound : ∀ᵐ x ∂intervalMeasure, ‖f x‖ ≤ C) : ‖f‖ ≤ C := by …Mentions: OAI.ThompsonNonamenability.Analytic.Hilbert, OAI.ThompsonNonamenability.Analytic.intervalMeasure
- theorem
OAI.ThompsonNonamenability.Analytic.norm_toLp_leline 38Source documentation
The same estimate for an explicitly supplied square-integrable function.
theorem norm_toLp_le {f : ℝ → Plane} (hf : MemLp f 2 intervalMeasure) {C : ℝ} (hC : 0 ≤ C) (hbound : ∀ᵐ x ∂intervalMeasure, ‖f x‖ ≤ C) : ‖hf.toLp f‖ ≤ C := by …Mentions: OAI.ThompsonNonamenability.Analytic.Plane, OAI.ThompsonNonamenability.Analytic.intervalMeasure
- theorem
OAI.ThompsonNonamenability.Analytic.hasDerivAt_of_quadratic_remainderline 47Source documentation
A quadratic norm remainder implies differentiability, without any pointwise choice of representatives in the codomain.
theorem hasDerivAt_of_quadratic_remainder {E : Type uE} [NormedAddCommGroup E] [NormedSpace ℝ E] {f : ℝ → E} {f' : E} {x C : ℝ} (hrem : ∀ᶠ h in 𝓝 (0 : ℝ), ‖f (x + h) - f x - h • f'‖ ≤ C * |h| ^ 2) : HasDerivAt f f' x := by …