Gap Between Operator Norm and Spectral Radius for the Square of Antidiagonal Block Operator Matrices

Abstract

In this work, the gap between operator norm and spectral radius for the square of antidiagonal block operator matrices in the direct sum of Banach spaces has been investigated, and also the gap between operator norm and numerical radius for the square of same matrices in the direct sum of Hilbert spaces has been studied.

Keywords

• antidiagonal operator matrix
• numerical radius
• operator norm
• spectral radius