TY - CONF
AU - Aiena, P.
AU - González, M.
AU - Martinón, A.
T1 - On the perturbation classes of continuous semi-Fredholm operators
LA - eng
PY - 2003
SP - 91
EP - 95
T2 - Glasgow Mathematical Journal
SN - 0017-0895
VL - 45
IS - 1
AB - We prove that the perturbation class of the upper semi-Fredholm operators from X into Y is the class of the strictly singular operators, whenever X is separable and Y contains a complemented copy of C[0,1]. We also prove that the perturbation class of the lower semi-Fredholm operators from X into Y is the class of the strictly cosingular operators, whenever X contains a complemented copy of ℓ1 and Y is separable. We can remove the separability requirements by taking suitable spaces instead of C[0, 1] or ℓ1.
DO - 10.1017/S0017089502001027
UR - https://portalciencia.ull.es/documentos/5e3adceb299952629a024b3d
DP - Dialnet - Portal de la Investigación
ER -