Romanyuk, A. S. Kolmogorov and trigonometric widths of the Besov classes \(B^r_{p,\theta}\) of multivariate periodic functions. (English) Zbl 1147.46026 Sb. Math. 197, No. 1, 69-93 (2006); translation from Mat. Sb. 197, No. 1, 71-96 (2006). Summary: Precise (in order) estimates of the Kolmogorov widths in the space \(L_q\), \(1<q<\infty\), of the classes \(B^r_{1,\theta}\) and \(B^r_{\infty,\theta}\) and also of the trigonometric widths of the classes \(B^r_{p,\theta}\) in \(L_q\) for \(p\) and \(q\) satisfying certain relations are obtained. Cited in 9 Documents MSC: 46E35 Sobolev spaces and other spaces of “smooth” functions, embedding theorems, trace theorems 41A46 Approximation by arbitrary nonlinear expressions; widths and entropy PDFBibTeX XMLCite \textit{A. S. Romanyuk}, Sb. Math. 197, No. 1, 69--93 (2006; Zbl 1147.46026); translation from Mat. Sb. 197, No. 1, 71--96 (2006) Full Text: DOI