A class of unitarily invariant norms on \(B(H)\) (Q2701583)

The authors characterize extreme points and strongly exposed points of generalized Schatten-class norms on the bounded operators \(B(H)\) on a Hilbert space \(H\): One takes \(k\in\mathbb{N}\) and \(c_1\geq\cdots\geq c_k> 0\) and defines NEWLINE\[NEWLINE\|A\|_{c,p}:= \Biggl(\sum^k_{i=1} c_is_i(A)^p\Biggr)^{1/p},NEWLINE\]NEWLINE \(s_i\)=singular numbers of \(A\in B(H)\). Using the results for the extreme points, they obtain a description of the corresponding isometric isomorphisms on \(B(H)\).