arXiv subjects
Publications and source records attributed to Othman Abad.
We extend the notion of generalized Drazin-Riesz inverse introduced for bounded linear operators in \cite{Ziv} to elements in a complex unital semi-simple Banach algebra. Several characterizations and properties of generalized Drazin-Riesz invertible elements are given. In particular, we extend those of \cite{AbZg1,Djor,Ziv}.
This paper is a continuation of our paper [Med. J. Math 19, Article number: 31 (2022)] in which we extended the notion of generalized Drazin-Riesz invertible operators to closed operators. We establish here, results relating the notion of closed generalized Drazin-Riesz invertibility with the theory of $C_{0}$-semigroups. Firstly, we generalize results obtained in the bounded case [1] to the context of closed operators. Secondly, we investigate when an infinitesimal generator $A$ of a given $C_{0}$-semigroup is closed generalized Drazin-Riesz invertible. An application to $C_{0}$-groups and abstract second order differential equations is proposed, and an example of a $C_{0}$-group with closed generalized Drazin-Riesz invertible infinitesimal generator is given.