Double piling structure of matrix monotone functions and of matrix convex functions II
Abstract
We continue the analysis in [H. Osaka and J. Tomiyama, Double piling structure of matrix monotone functions and of matrix convex functions, Linear and its Applications 431(2009), 1825 - 1832] in which the followings three assertions at each label are discussed: (1) and is -convex in . (2)For each matrix with its spectrum in and a contraction in the matrix algebra , . (3)The function is -monotone in . We know that two conditions and are equivalent and if with is -convex, then is -monotone. In this note we consider several extra conditions on to conclude that the implication from to is true. In particular, we study a class of functions with conditional positive Lowner matrix which contains the class of matrix -monotone functions and show that if with and is -monotone, then is -convex. We also discuss about the local property of -convexity.
Keywords
Cite
@article{arxiv.1104.3372,
title = {Double piling structure of matrix monotone functions and of matrix convex functions II},
author = {Hiroyuki Osaka and Jun Tomiyama},
journal= {arXiv preprint arXiv:1104.3372},
year = {2011}
}
Comments
13pages