Norm inequalities for vector functions

Abstract

We study vector functions of Rn into itself, which are of the form x→g(|x|)x, where g:(0,∞)→(0,∞) is a continuous function and call these radial functions. In the case when g(t)=tc for some c∈R, we find upper bounds for the distance of image points under such a radial function. Some of our results refine recent results of L. Maligranda and S.S. Dragomir. In particular, we study quasiconformal mappings of this simple type and obtain norm inequalities for such mappings. © 2011 Elsevier Inc.