Notes on some spectral radius and numerical radius inequalities
Volume 227 / 2015
Studia Mathematica 227 (2015), 97-109 MSC: Primary 47A12, 47A30, 47A63; Secondary 47B15. DOI: 10.4064/sm227-2-1
We prove numerical radius inequalities for products, commutators, anticommutators, and sums of Hilbert space operators. A spectral radius inequality for sums of commuting operators is also given. Our results improve earlier well-known results.