Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5773133 | Linear Algebra and its Applications | 2017 | 13 Pages |
Abstract
Let C1,C2,â¦,Ck be positive matrices in Mn and f be a continuous real-valued function on [0,â). In addition, consider Φ as a positive linear functional on Mn and defineÏ(t1,t2,t3,â¦,tk)=Φ(f(t1C1+t2C2+t3C3+â¦+tkCk)), as a k variables continuous function on [0,â)Ãâ¦Ã[0,â). In this paper, we show that if f is an operator convex function of order mn, then Ï is a k variables operator convex function of order (n1,â¦,nk) such that m=n1n2â¦nk. Also, if f is an operator monotone function of order nk+1, then Ï is a k variables operator monotone function of order n. In particular, if f is a non-negative operator decreasing function on [0,â), then the function tâΦ(f(A+tB)) is an operator decreasing and can be written as a Laplace transform of a positive measure.
Related Topics
Physical Sciences and Engineering
Mathematics
Algebra and Number Theory
Authors
Hamed Najafi,