The sigma g-Drazin inverse and the generalized Mbekhta decomposition
A Dajic, JJ Koliha
INTEGRAL EQUATIONS AND OPERATOR THEORY | SPRINGER BASEL AG | Published : 2007
In this paper we define and study an extension of the g-Drazin for elements of a Banach algebra and for bounded linear operators based on an isolated spectral set rather than on an isolated spectral point. We investigate salient properties of the new inverse and its continuity, and illustrate its usefulness with an application to differential equations. Generalized Mbekhta subspaces are introduced and the corresponding extended Mbekhta decomposition gives a characterization of circularly isolated spectral sets. © 2006 Birkhäuser Verlag Basel/Switzerland.