On estimates of M-term approximations of the Sobolev class in the Lorentz space


Лоренц кеңiстiгiндегi Соболев класының M-мүшелiк жуықтауларын бағалау туралы
Об оценках M-членных приближений класса Соболева в пространстве Лоренца
Akishev G. Myrzagaliyeva A.K.
2024E.A. Buketov Karaganda University Publish house

Bulletin of the Karaganda University. Mathematics Series
2024#114Issue 24 - 21 pp.

In the paper spaces of periodic functions of several variables were considered, namely the Lorentz space L2,τ(Tm), the class of functions with bounded mixed fractional derivative W2r, 1 ≤ τ < ∞, and the order of the best M-term approximation of a function f ∈ Lp,τ(Tm) by trigonometric polynomials was studied. The article consists of an introduction, a main part, and a conclusion. In the introduction, basic concepts, definitions and necessary statements for the proof of the main results were considered. One can be found information about previous results on the mentioned topic. In the main part, exact-order estimates are established for the best M-term approximations of functions of the Sobolev class W2r1 in the norm of the space Lp,τ2(Tm) for various relations between the parameters p,τ1,τ2.

Lorentz space , M-term approximation , mixed derivative , Sobolev class , trigonometric polynomial

Text of the article Перейти на текст статьи

Kazakhstan Branch of Lomonosov Moscow State University, 11 Kazhymukan Street, Astana, 010010, Kazakhstan
Astana IT University, 55/11 Mangilik El Avenue, Astana, 010000, Kazakhstan

Kazakhstan Branch of Lomonosov Moscow State University
Astana IT University

10 лет помогаем публиковать статьи Международный издатель

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