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arXiv · 1405.4688

Some operator convex functions of several variables

Zhihua Zhang
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Abstract

We obtain operator concavity (convexity) of some functions of two or three variables by using perspectives of regular operator mappings of one or several variables. As an application, we obtain, for $ 0<p < 1,$ concavity, respectively convexity, of the Frechét differential mapping associated with the functions $t \to t^{1+p} $ and $t \to t^{1-p}.$

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Zhihua Zhang. 2014-06-06. Some operator convex functions of several variables. https://arxiv.org/abs/1405.4688

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