Modulus of convexity for operator convex functions

Abstract

Given an operator convex function f(x), we obtain an operator-valued lower bound for cf(x) + (1 − c)f(y) − f(cx + (1 − c)y), c ∈ [0, 1]. The lower bound is expressed in terms of the matrix Bregman divergence. A similar inequality is shown to be false for functions that are convex but not operator convex.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jul 21, 2014
Source ID
10.1063/1.4890292

Entities

People

  • Isaac H. Kim

Organizations

  • Army Research Office
  • National Science Foundation
  • United States Department of Energy

Tags

Readers

  • Calculus or Mathematical Analysis
  • Operations Research