Some Remarks on Perturbation Classes of Semi-Fredholm and Fredholm Operators
نویسندگان
چکیده
We show the existence of Banach spaces X, Y such that the set of strictly singular operators (X,Y) (resp., the set of strictly cosingular operators Ꮿ(X,Y)) would be strictly included in F + (X,Y) (resp., F − (X,Y)) for the nonempty class of closed densely defined upper semi-Fredholm operators Φ + (X,Y) (resp., for the nonempty class of closed densely defined lower semi-Fredholm operators Φ − (X,Y)). This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution , and reproduction in any medium, provided the original work is properly cited.
منابع مشابه
Research Article Some Remarks on Perturbation Classes of Semi-Fredholm and Fredholm Operators
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ورودعنوان ژورنال:
- Int. J. Math. Mathematical Sciences
دوره 2007 شماره
صفحات -
تاریخ انتشار 2007