Abilov, V. A.; Abilova, F. V. Approximation of functions by the Fourier-Bessel sums. (English. Russian original) Zbl 1029.42023 Russ. Math. 45, No. 8, 1-7 (2001); translation from Izv. Vyssh. Uchebn. Zaved., Mat. 2001, No. 8, 3-9 (2001). There are proved the direct and inverse approximation theorems as well as the order of the \(n\)-widths according to Kolmogorov is given. Reviewer: Włodzimierz Łenski (Poznań) Cited in 35 Documents MSC: 42C15 General harmonic expansions, frames 41A46 Approximation by arbitrary nonlinear expressions; widths and entropy 42C10 Fourier series in special orthogonal functions (Legendre polynomials, Walsh functions, etc.) 41A50 Best approximation, Chebyshev systems Keywords:best approximation; Fourier-Bessel sums; \(n\)-widt according to Kolmogorov; Fourier-Bessel polynomials PDFBibTeX XMLCite \textit{V. A. Abilov} and \textit{F. V. Abilova}, Russ. Math. 45, No. 8, 3--9 (2001; Zbl 1029.42023); translation from Izv. Vyssh. Uchebn. Zaved., Mat. 2001, No. 8, 3--9 (2001)