ON SPECTRA OF 2-ISOMETRIC OPERATORS
ON SPECTRA OF 2-ISOMETRIC OPERATORS
한국수학교육학회지시리즈B:순수및응용수학 / Journal of the Korean Society of Mathematical Education Series B: Theoretical Mathematics and Pedagogical Mathematics, (P)3059-0604; (E)3059-1309
2009, v.16 no.3, pp.277-281
Yang, Young-Oh
(DEPARTMENT OF MATHEMATICS AND INFORMATION, CHEJU NATIONAL UNIVERSITY)
Kim, Cheoul-Jun
(DEPARTMENT OF MATHEMATICS AND INFORMATION, CHEJU NATIONAL UNIVERSITY)
Yang, Young-Oh,
&
Kim, Cheoul-Jun.
(2009). ON SPECTRA OF 2-ISOMETRIC OPERATORS, 16(3), 277-281.
Abstract
A Hilbert space operator T is a 2-isometry if $T^{{\ast}2}T^2\;-\;2T^{\ast}T+I$ = O. We shall study some properties of 2-isometries, in particular spectra of a non-unitary 2-isometry and give an example. Also we prove with alternate argument that the Weyl's theorem holds for 2-isometries.
- keywords
-
2-isometry,
spectrum,
Weyl spectrum,
Weyl's theorem