Alphabeta Math

Fourier Multipliers and Sobolev Characterisations

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✓ 8 results · all verified · 2 also independently AI-judged
Every result on this page is machine-checked by a proof checker and read in full and owner-audited; the judge is an additional, independent cross-model AI review of the proofs. The 6 not AI-judged were verified by owner audit (typically over a confirmed judge false positive), not failures.
1 · Prerequisites
Abstract Algebra
Combinatorics
Complex Analysis
Coxeter Groups
Differential Geometry
Functional Analysis
Linear Algebra
Measure Theory
Partial Differential Equations
Real Analysis
Set Theory
Topology
2 · Logical flowchart

3 · Items

Definition

Translation-invariant Fourier multiplier on the Schwartz core

Lemma

Exact L2 Fourier multiplier norm

Definition

Lp Fourier multiplier and its norm

Theorem

Hausdorff–Young for periodic Fourier coefficients

Theorem

Hausdorff–Young for the Euclidean Fourier transform

Definition

Mihlin smoothness convention above half the dimension

Lemma

Distributional derivatives are polynomial Fourier multipliers

Theorem

Integer-order W^k,2 and Hᵏ agree with equivalent norms

Theorem

Real-order Hˢ as weighted Fourier distributions

Definition

Japanese-bracket and Laplacian Bessel-potential operators

Lemma

Bessel potentials shift Sobolev order

Corollary

Conjugate duality of Hˢ and H⁻ˢ

Sources