Some approximation theorems in Fourier-Jacobi analysis and Boas type results for Nikol’skii spaces
摘要
We obtain results on simultaneous approximation and a sharpened version of the inverse approximation theorem in Fourier-Jacobi analysis setting. Using above cited version we prove Boas equivalence results for Nikol’skii and Hölder-Zygmund spaces defined by Jacobi translation and Jacobi differential operator.