SEMI-BROWDER OPERATORS AND PERTURBATIONS

Authors
Citation
V. Rakocevic, SEMI-BROWDER OPERATORS AND PERTURBATIONS, Studia Mathematica, 122(2), 1997, pp. 131-137
Citations number
22
Categorie Soggetti
Mathematics, General",Mathematics
Journal title
ISSN journal
00393223
Volume
122
Issue
2
Year of publication
1997
Pages
131 - 137
Database
ISI
SICI code
0039-3223(1997)122:2<131:SOAP>2.0.ZU;2-Z
Abstract
An operator in a Banach space is called upper (resp. lower) semi-Browd er if it is upper (lower) semi-Fredholm and has a finite ascent (resp. descent). An operator in a Banach space is called semi-Browder if it is upper semi-Browder or lower semi-Browder. We prove the stability of the semi-Browder operators under commuting Riesz operator perturbatio ns. As a corollary we get some results of Grabiner [6], Kaashoek and L ay [8], Lay [11], Rakocevic [15] and Schechter [16].