Some New Fourier and Jackson-Nikolskii Type Inequalities in Unbounded Orthonormal Systems


Akishev G. Persson L.E. Singh H.
16 September 2021Tuncer ACAR

Constructive Mathematical Analysis
2021#4Issue 3291 - 304 pp.

We consider the generalized Lorentz space Lψ, q defined via a continuous and concave function ψ and the Fourier series of a function with respect to an unbounded orthonormal system. Some new Fourier and Jackson-Nikolskii type inequalities in this frame are stated, proved and discussed. In particular, the derived results generalize and unify several well-known results but also some new applications are pointed out.

Fourier inequalities , generalized Lorentz spaces , Inequalities , Jackson-Nikolskii inequality , unbounded orthonormal system

Text of the article Перейти на текст статьи

Lomonosov Moscow State University, Department of Mathematics and Informatics, Kazakhstan Branch of MSU, Nur-Sultan, Kazakhstan
Institute of Natural Sciences and Mathematics, Ural Federal University, Yekaterinburg, Russian Federation
UIT the Arctic University of Norway, Department of Computer Science and Computational Engineering, Narvik, Norway
Karlstad University, Department of Mathematics and Computer Science, Sweden

Lomonosov Moscow State University
Institute of Natural Sciences and Mathematics
UIT the Arctic University of Norway
Karlstad University

10 лет помогаем публиковать статьи Международный издатель

Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026