Modulus of continuity of operator functions

Modulus of convexity for operator convex functions

Most of the interesting examples deal with operators that are positive semi-definite. We shall follow the same convention in this paper. Operator convex functions are known to satisfy a number of interesting properties. An important discovery was made by Hansen and Pederson, who used Eq.1 in order to obtain an operator generalization of the Jensen inequality.[1] Recently, Effros provided an ele...

Majorization of the Modulus of Continuity of Analytic Functions

Let G be a bounded domain in the complex plane, let f be analytic in G and continuous in G, and let μ be a majorant, that is, a non-negative non-decreasing function defined for t ≥ 0 such that μ(2t) ≤ 2μ(t) for all t ≥ 0. Suppose that z1 ∈ ∂G and that |f(z1) − f(z2)| ≤ μ(|z1 − z2|) for all z2 ∈ ∂G. We show that then |f(z1)−f(z2)| ≤ Cμ(|z1−z2|) for all z2 ∈ G where C = 3456. If the assumption is...

The modulus of continuity of analytic functions and CR- geometry

1 Introduction Contour and solid modulus of continuity. The one-dimensional case There has been an extensive study of the relation between the " contour " and the " solid " moduli of continuity for analytic functions in planar domains, starting with the following beautiful result of Hardy and Littlewood. For a domain G in C n (n ≥ 1) we denote as usual by A(G) the algebra of analytic functions ...

On genuine Lupac{s}-Beta operators and modulus of continuity

In the present article we discuss approximation properties of genuine Lupac{s}-Beta operators of  integral type. We establish quantitative asymptotic formulae and a direct estimate in terms of Ditzian-Totik modulus of continuity. Finally we mention  results on the weighted modulus of continuity for the genuine operators.

Modulus of continuity on parts of the boundary and solid modulus of continuity