caa a22 4500 386372209 CHVBK 20180307112001.0 cr unu---uuuuu 161130e198905 xx s 000 0 eng 10.1017/S0017089500007771 doi S0017089500007771 pii (NATIONALLICENCE)cambridge-10.1017/S0017089500007771 Searcóid Mícheál Ó. Roinn na Matamaitice, Coláiste na Hollscoile, Baile Átha Cliath 4, Éire. A contribution to the solution of the compact correction problem for operators on a Banach space [Elektronische Daten] [Mícheál Ó Searcóid] We consider the hypothesis that an operator T on a given Banach space can always be perturbed by a compact operator K in such a way that, whenever a complex number A is in the semi-Fredholm region of T + K, then T + K - λ is either bounded below or surjective. The hypothesis has its origin in the work of West [11], who proved it for Riesz operators on Hilbert space. In this paper, we reduce the general Banach space problem to one of considering only operators of a special type, operators which are, in a spectral sense, natural generalizations of the Riesz operators studied by West. Copyright © Glasgow Mathematical Journal Trust 1989 Glasgow Mathematical Journal Cambridge University Press 31/2(1989-05), 219-229 0017-0895 31:2<219 1989 31 GMJ https://doi.org/10.1017/S0017089500007771 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0017089500007771 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Searcóid Mícheál Ó. Roinn na Matamaitice, Coláiste na Hollscoile, Baile Átha Cliath 4, Éire NATIONALLICENCE 773 0- Glasgow Mathematical Journal Cambridge University Press 31/2(1989-05), 219-229 0017-0895 31:2<219 1989 31 GMJ CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge