M. G. Magomed-Kasumov

Approximation Properties of Fourier Sums in Jacobi–Sobolev Polynomials

Uniform convergence of Fourier series in the system of Sobolev-orthogonal polynomials associated with Jacobi polynomials

Necessary and sufficient conditions are obtained on the exponents $\alpha$ and $\beta$ under which the Fourier series in the Sobolev system of polynomials $\mathcal{P}_r^{\alpha,\beta}$ associated with the Jacobi polynomials converge uniformly on $[-1,1]$ to functions in the Sobolev space $W^r_{L^1_{\rho(\alpha,\beta)}...