paper

The fast track to Löwner's theorem

arXiv:1112.0098 · doi:10.1016/j.laa.2013.01.022

Abstract

The operator monotone functions defined in the positive half-line are of particular importance. We give a version of the theory in which integral representations for these functions can be established directly without invoking Löwner's detailed analysis of matrix monotone functions of a fixed order or the theory of analytic functions. We found a canonical relationship between positive and arbitrary operator monotone functions defined in the positive half-line, and this result effectively reduces the theory to the case of positive functions. MSC2010 classification: 26A48; 26A51; 47A63. Key words and phrases: operator monotone function; integral representation; Löwner's theorem.

Final version to be published. Proof of Bendat and Sherman's theorem added

References in corpus (1)

Cited by in corpus (21)