TY  - JOUR
ID  - Gil2021
LB  - Gil2021
AU  - Gil', Michael
TI  - Spectrum localization of a perturbed operator in a strip and applications
ST  - Spectrum localization of a perturbed operator in a strip and applications
JO  - Opuscula Math.
JA  - Opuscula Math.
JF  - Opuscula Mathematica
PY  - 2021
VL  - 41
IS  - 3
SP  - 395
EP  - 412
DO  - https://doi.org/10.7494/OpMath.2021.41.3.395
UR  - https://doi.org/10.7494/OpMath.2021.41.3.395
AB  - Let \(A\) and \(\tilde{A}\) be bounded operators in a Hilbert space. We consider the following problem: let the spectrum of \(A\) lie in some strip. In what strip the spectrum of \(\tilde{A}\) lies if \(A\) and \(\tilde{A}\) are "close"? Applications of the obtained results to integral operators and matrices are also discussed. In addition, we apply our perturbation results to approximate the spectral strip of a Hilbert-Schmidt operator by the spectral strips of finite matrices.
KW  - operator
KW  - spectrum
KW  - perturbation
KW  - approximation
KW  - integral operator
KW  - matrix
SN  - 1232-9274
ER  -