BESOV SPACES AND K-FUNCTIONALS IN l_P, O

摘要

We investigate Besov spaces and their connection with trigonometric polynomial approx- imation in L_p[-π,π], algebraic polynomial approximation in L_p[-1,1], algebraic polynomial ap- proximation in L_p(s), and entire function of exponential type approximation in L_p(r), and char- acterize k-functionals for certain pairs of function spaces including