Invertibility properties of operator matrices on Hilbert spaces
نویسندگان
چکیده
Denote by $$T_n^d(A)$$ an upper triangular operator matrix of dimension n whose diagonal entries are given and the others unknown. In this article, we provide necessary sufficient conditions for various types Fredholm Weyl completions . As consequences, recover many known results Zhang Wu (J Math Anal Appl 392(2):103–110, 2012) case $$n=2$$ already existing in literature, as well some perturbation Huang (Acta Sin (Engl Ser) 36(7):783–796, 2020; Ann Funct 11(3):780–798, 2020) arbitrary $$n\ge 2$$
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ژورنال
عنوان ژورنال: Advances in operator theory
سال: 2023
ISSN: ['2538-225X', '2662-2009']
DOI: https://doi.org/10.1007/s43036-023-00268-8