Documentation

LeanPool.HighContrastHomogenization.Support.Book.Ch02.Theorems.MultiscaleEllipticity.Basic

Coarse-graining support: Support.Book.Ch02.Theorems.MultiscaleEllipticity.Basic #

Imported from the Apache-2.0 CoarseGraining development at commit c7ddd76c08ade64fed1b8d2ca51be14dfee8deb4.

Basic Helpers for Chapter 2.5 Multiscale Ellipticity #

This file contains the matrix-norm, finite-supremum, and scale-weight helper lemmas used by the public multiscale ellipticity theorem package.

theorem HCPolySupport.Book.Ch02.matNorm_le_sum_abs_entries {d : ℕ} (A : Mat d) :
matNorm A ≤ ∑ i : Fin d, ∑ j : Fin d, |A i j|

The legacy Frobenius norm is bounded by the entrywise l¹ norm.

Triangle inequality for the Chapter 2 matrix norm around a center.

The Chapter 2 matrix norm around a center is controlled by the entrywise l¹ size of the centered matrix.

theorem HCPolySupport.Book.Ch02.matrixNorm_le_center_add_sum_abs_sub_entries_of_matLoewnerLE {d : ℕ} {A B center : Mat d} (hA : Matrix.PosSemidef A) (hB : Matrix.PosSemidef B) (hAB : MatLoewnerLE A B) :
matrixNorm A ≤ matrixNorm center + ∑ i : Fin d, ∑ j : Fin d, |B i j - center i j|

A positive semidefinite matrix below B in Löwner order is controlled by the norm of any deterministic center plus the entrywise centered size of B.

theorem HCPolySupport.Book.Ch02.finsetSupReal_congr {α : Type u_1} (s : Finset α) {f g : α → ℝ} (hfg : ∀ x ∈ s, f x = g x) :
theorem HCPolySupport.Book.Ch02.finsetSupReal_image {α : Type u_1} {β : Type u_2} [DecidableEq β] (s : Finset α) (φ : α → β) (f : β → ℝ) (g : α → ℝ) (hfg : ∀ x ∈ s, f (φ x) = g x) :
theorem HCPolySupport.Book.Ch02.finsetSupReal_nonneg {α : Type u_1} (s : Finset α) (f : α → ℝ) (hf : ∀ x ∈ s, 0 ≤ f x) :
theorem HCPolySupport.Book.Ch02.finsetSupReal_mono {α : Type u_1} (s : Finset α) (hs : s.Nonempty) {f g : α → ℝ} (hfg : ∀ x ∈ s, f x ≤ g x) :
theorem HCPolySupport.Book.Ch02.finsetSupReal_const_mul_le {α : Type u_1} (s : Finset α) (hs : s.Nonempty) {c : ℝ} (hc : 0 ≤ c) (f : α → ℝ) :
(finsetSupReal s fun (x : α) => c * f x) ≤ c * finsetSupReal s f
theorem HCPolySupport.Book.Ch02.finsetSupReal_le_of_subset {α : Type u_1} (s t : Finset α) (hs : s.Nonempty) (hst : ↑s ⊆ ↑t) (f : α → ℝ) :
theorem HCPolySupport.Book.Ch02.finsetSupReal_le {α : Type u_1} (s : Finset α) (hs : s.Nonempty) {f : α → ℝ} {C : ℝ} (hC : ∀ x ∈ s, f x ≤ C) :
theorem HCPolySupport.Book.Ch02.infinityWeight_le_one {s : ℝ} (hs : 0 ≤ s) (n : ℕ) :
Real.rpow 3 (-2 * s * ↑n) ≤ 1
theorem HCPolySupport.Book.Ch02.infinityWeight_le_of_le {t s : ℝ} (hts : t ≤ s) (n : ℕ) :
Real.rpow 3 (-2 * s * ↑n) ≤ Real.rpow 3 (-2 * t * ↑n)
theorem HCPolySupport.Book.Ch02.infinityWeight_shift (s : ℝ) (h n : ℕ) :
Real.rpow 3 (-2 * s * ↑n) = Real.rpow 3 (2 * s * ↑h) * Real.rpow 3 (-2 * s * ↑(n + h))