Unitarily invariant norm inequalities for operators

We present several norm inequalities for Hilbert space operators. In particular, we prove that if A1,A2,…,An∈B(H), then |||A1A2∗+A2A3∗+⋯+AnA1∗|||⩽∑i=1nAiAi∗for all unitarily invariant norms. We also show that if A1,A2,A3,A4 are projections in B(H), then ∑i=14(-1)i+1Ai⊕0⊕0⊕0⩽|||(A1+|A3A1|)⊕(A2+|A4A2|...

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Bibliographic Details
Main Authors: M. Erfanian Omidvar, M.S. Moslehian, A. Niknam
Format: Article
Language:English
Published: SpringerOpen 2012-04-01
Series:Journal of the Egyptian Mathematical Society
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S1110256X11000277