We study the filtering of the perspective of a regular operator map of several variables through a completely positive linear map. By this method we are able to extend known operator inequalities of two variables to several variables, with applications in the theory of operator means of several variables. We also extend Lieb and Ruskai’s convexity theorem from two to operator variables for any natural number .
"Perspectives and completely positive maps." Ann. Funct. Anal. 8 (2) 168 - 176, May 2017. https://doi.org/10.1215/20088752-3784269