2014/11/23 by Koenraad M. R. Audenaert, Audenaert, Koenraad M. R.
Mathematics · #FOS: Mathematics #Functional Analysis (math.FA) #math.FA
paper · pdf · doi:10.48550/arxiv.1411.6234
4 pages
arxiv created 2014/11/23 · arxiv updated 2014/11/25
For k=1,…,K, let Ak and Bk be positive semidefinite matrices such that, for each k, Ak commutes with Bk. We show that, for any unitarily invariant norm, |||∑k=1K AkBk||| ≤ ||| (∑k=1K Ak) (∑k=1K Bk)|||.