A weak-type inequality for uniformly bounded trigonometric polynomials

Autor: E. D. Livshits
Rok vydání: 2013
Předmět:
Zdroj: Proceedings of the Steklov Institute of Mathematics. 280:208-219
ISSN: 1531-8605
0081-5438
DOI: 10.1134/s0081543813010148
Popis: This paper is devoted to refining the Bernstein inequality. Let D be the differentiation operator. The action of the operator Λ = D/n on the set of trigonometric polynomials Tn is studied: the best constant is sought in the inequality between the measures of the sets {x ∈ T: |Λt(x)| > 1} and {x ∈ T: |t(x)| > 1}. We obtain an upper estimate that is order sharp on the set of uniformly bounded trigonometric polynomials TnC = {t ∈ Tn: ‖t‖ ≤ C}.
Databáze: OpenAIRE