Orthogonal expansions and the error of weighted polynomial approximation for erdös weights

Abstract
Some (C, 1) bounds for orthogonal expansions associated with Erdös weights are established. Roughly speaking, Erdös weights are weights of the form W := e Q , where Q is even, continuous and has faster than polynomial growth at infinity. Typical examples are or , and so on. We shall use these bounds together with Bohr-type inequalities, to establish L p , 1 ≤ p ≤ ∞, Jackson-Favard inequalities.