$A$-spectral permanence property for $C^{\ast }$-algebras

Abstract

For a positive element $A$ of a $C^{\ast }$-algebra $\mathfrak{A}$, let ${\Vert X\Vert }_A$ denote the $A$-operator semi-norm of $X\in \mathfrak{A}$. In this paper, we aim to introduce and study the notion of $A$-spectrum for $X$ such that ${\Vert X\Vert }_A<\infty$. In particular when $A$ is well-supported, we establish an $A$-spectral permanence property for $C^{\ast }$-algebras.

15 pages