Concavity of certain matrix trace and norm functions. II.

We refine Epstein's method to prove joint concavity/convexity of matrix trace functions of Lieb type Tr f ( Φ ( A p ) 1 / 2 Ψ ( B q ) Φ ( A p ) 1 / 2 ) and symmetric (anti-) norm functions of the form ‖ f ( Φ ( A p ) σ Ψ ( B q ) ) ‖ , where Φ and Ψ are positive linear maps, σ is an operator mean, and f ( x γ ) with a certain power γ is an operator monotone function on ( 0 , ∞ ) . Moreover, the variational method of Carlen, Frank and Lieb is extended to general non-decreasing convex/concave functions on ( 0 , ∞ ) so that we prove joint concavity/convexity of more trace functions of Lieb type. [ABSTRACT FROM AUTHOR]