MULTIPLIERS WITH RESPECT TO ORTHOGONAL EXPANSIONS IN BANACH SPACES
Jüri Lippus · Proceedings of the Estonian Academy of Sciences Physics Mathematics · 1993
A necessary and sufficient condition for multipliers of generalized Lipschitz classes in certain Banach spaces is obtained.The majorant of the modulus of continuity is supposed to be slowly decreasing.For the one-dimensional periodic case the result was known earlier.