TY  - JOUR
ID  - Gil2015
LB  - Gil2015
AU  - Gil', Michael
TI  - Simple eigenvectors of unbounded operators of the type "normal plus compact"
ST  - Simple eigenvectors of unbounded operators of the type "normal plus compact"
JO  - Opuscula Math.
JA  - Opuscula Math.
JF  - Opuscula Mathematica
PY  - 2015
VL  - 35
IS  - 2
SP  - 161
EP  - 169
DO  - http://dx.doi.org/10.7494/OpMath.2015.35.2.161
UR  - http://dx.doi.org/10.7494/OpMath.2015.35.2.161
AB  - The paper deals with operators of the form \(A=S+B\), where \(B\) is a compact operator in a Hilbert space \(H\) and \(S\) is an unbounded normal one in \(H\), having a compact resolvent. We consider approximations of the eigenvectors of \(A\), corresponding to simple eigenvalues by the eigenvectors of the operators \(A_n=S+B_n\) (\(n=1,2, \ldots\)), where \(B_n\) is an \(n\)-dimensional operator. In addition, we obtain the error estimate of the approximation.
KW  - Hilbert space
KW  - linear operators
KW  - eigenvectors
KW  - approximation
KW  - integro-differential operators
KW  - Schatten-von Neumann operators
SN  - 1232-9274
ER  -