English

On Bernstein type quantitative estimates for Ornstein non-inequalities

Functional Analysis 2023-07-12 v2 Classical Analysis and ODEs

Abstract

For the sequence of multi-indexes {αi}i=1m\{\alpha_i\}_{i=1}^{m} and β\beta we study the inequality DβfL1(Td)KNj=1mDαjfL1(Td), \|D^{\beta} f\|_{L_1(\mathbb{T}^d)}\leq K_N \sum_{j= 1}^{m} \|D^{\alpha_j}f\|_{L_1(\mathbb{T}^d)}, where ff is a trigonometric polynomial of degree at most NN on dd-dimensional torus. Assuming some natural geometric property of the set {αj}{β}\{\alpha_j\}\cup\{\beta\} we show that KNC(lnN)ϕ, K_{N}\geq C \left(\ln N\right)^{\phi}, where ϕ<1\phi<1 depends only on the set {αj}{β}\{\alpha_j\}\cup\{\beta\}.

Keywords

Cite

@article{arxiv.2206.13666,
  title  = {On Bernstein type quantitative estimates for Ornstein non-inequalities},
  author = {Krystian Kazaniecki and Michał Wojciechowski},
  journal= {arXiv preprint arXiv:2206.13666},
  year   = {2023}
}

Comments

Presentation improved, typos corrected

R2 v1 2026-06-24T12:06:08.616Z