2018/08/09 by Cristina Benea, Benea, Cristina, Camil Muscalu +1
Mathematics · #Advanced Harmonic Analysis Research #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #Mathematical Analysis and Transform Methods #Mathematical Approximation and Integration #math.CA
paper · pdf · doi:10.48550/arxiv.1808.03248
38 pages, technical revision of Proposition4.1
openalex publication_date 2018/08/09 · arxiv created 2019/08/06 · arxiv updated 2019/08/08 · openalex created_date 2022/08/04 · openalex updated_date 2026/07/28
We prove that for any LQ-valued Schwartz function f defined on ℝd, one has the multiple vector-valued, mixed norm estimate ‖ f ‖LP(LQ) \lesssim ‖ S f ‖LP(LQ) valid for every d-tuple P and every n-tuple Q satisfying 0 < P, Q < ∞ componentwise. Here S:= Sd1⊗ ... ⊗ SdN is a tensor product of several Littlewood-Paley square functions Sdj defined on arbitrary Euclidean spaces ℝdj for 1≤ j≤ N, with the property that d1 + ... + dN = d. This answers a question that came up implicitly in our recent works and completes in a natural way classical results of the Littlewood-Paley theory. The proof is based on the helicoidal method introduced by the authors.