Year: 2017
Type: article
Abstract: We consider the operator A = U + K , where U is a unitary operator and K is a compact one. An eigenvalue of A is said to be a non-unitary one, if | | = 1 . We derive inequalities for sums of absolute values of the non-unitary eigenvalues. Applications of these inequalities to operator functions, spectrum perturbations and operator equations are also discussed.
Source: Operators and Matrices
DOI: 10.7153/oam-11-32
Author: M. I. Gil'
Language: English
Subfield: Mathematical Physics
Field: Mathematics
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4238052935