Right (Or Left) Invertibility of Bounded and Unbounded Operators and Applications to the Spectrum of Products

Abstract

This paper is mainly concerned with proving $\sigma (AB)=\sigma (BA)$ for two linear and non necessarily bounded operators $A$ and $B$. The main tool is left and right invertibility of bounded and unbounded operators.

arXiv comment09 pages

Cited by in corpus (2)

• On The Absolute Value of The Product and the Sum of Linear Operators
• New proofs of the operator monotony of the square root and the inverse