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A characterization of unbounded Fredholm operators

A. G. Ramm
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Abstract

This paper is a continuation of the paper (A.G.Ramm, Amer. Math. Monthly, 108, N 9, (2001), 855-860), where bounded Fredholm operators are studied. The theory of bounded linear Fredholm-type operators is presented in many texts. This paper is written for a broad audience and the author tries to give simple and short arguments.

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A. G. Ramm. 2003-01-31. A characterization of unbounded Fredholm operators. https://arxiv.org/abs/math/0301385

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