OAI/Geometry/EinsteinFour/ScalarLpVariation.lean
5 declarations, 0 contain sorry, 0 declared as axioms
Differentiation of the scalar p-moment along bounded directions. The base function need only belong to Lp, including at its zero set.
- theorem
OAI.PositiveEinsteinFour.Geometry.scalarMoment_point_derivativeline 18 - theorem
OAI.PositiveEinsteinFour.Geometry.scalarMoment_derivative_boundline 28 - theorem
OAI.PositiveEinsteinFour.Geometry.scalarLpMoment_hasDerivAtline 61Source documentation
A bounded measurable direction differentiates the p-moment of an arbitrary Lp function. No nonvanishing or regularity assumption is placed on the latter.
theorem scalarLpMoment_hasDerivAt {p : ℝ} (hp : 2 < p) {f b : X → ℝ} (hf : MemLp f (ENNReal.ofReal p) μ) (hb : AEStronglyMeasurable b μ) {B : ℝ} (hB : 0 ≤ B) (hbBound : ∀ᵐ x ∂μ, |b x| ≤ B) : Integrable (fun x => |f x| ^ (p - 2) * f x * b x) μ ∧ HasDerivAt (fun t : ℝ => ∫ x, |f x + t * b x| ^ p ∂μ) (p * ∫ x, |f x| ^ (p - 2) * f x * b x ∂μ) 0 := by … - theorem
OAI.PositiveEinsteinFour.Geometry.scalarLpMoment_hasDerivAt_lpline 120Source documentation
Lp-space version, ready for a weak variational equation.
theorem scalarLpMoment_hasDerivAt_lp {p : ℝ} (hp : 2 < p) (f : Lp ℝ (ENNReal.ofReal p) μ) {b : X → ℝ} (hb : AEStronglyMeasurable b μ) {B : ℝ} (hB : 0 ≤ B) (hbBound : ∀ᵐ x ∂μ, |b x| ≤ B) : HasDerivAt (fun t : ℝ => ∫ x, |f x + t * b x| ^ p ∂μ) (p * ∫ x, |f x| ^ (p - 2) * f x * b x ∂μ) 0 := … - theorem
OAI.PositiveEinsteinFour.Geometry.scalarLpMoment_hasDerivAt_continuousline 130Source documentation
On a compact base every continuous, hence every smooth, test direction automatically satisfies the required domination.
theorem scalarLpMoment_hasDerivAt_continuous [TopologicalSpace X] [OpensMeasurableSpace X] [CompactSpace X] {p : ℝ} (hp : 2 < p) {f : X → ℝ} (hf : MemLp f (ENNReal.ofReal p) μ) (b : C(X, ℝ)) : Integrable (fun x => |f x| ^ (p - 2) * f x * b x) μ ∧ HasDerivAt (fun t : ℝ => ∫ x, |f x + t * b x| ^ p ∂μ) (p * ∫ x, |f x| ^ (p - 2) * f x * b x ∂μ) 0 := …