Perturbation of m-isometries by nilpotent operators

0436815 - MÚ 2015 RIV US eng J - Journal Article
Bermúdez, T. - Martinón, A. - Müller, Vladimír - Noda, J. A.
Perturbation of m-isometries by nilpotent operators.
Abstract and Applied Analysis. Roč. 2014, September (2014), s. 745479. ISSN 1085-3375
R&D Projects: GA ČR(CZ) GA14-07880S
Institutional support: RVO:67985840
Keywords : pertubation * m-isometries
Subject RIV: BA - General Mathematics
Impact factor: 1.274, year: 2013
http://www.hindawi.com/journals/aaa/2014/745479/

We prove that if T is an m-isometry on a Hilbert space and Q an n-nilpotent operator commuting with T, then T+Q is a (2n+m-2)-isometry. Moreover, we show that a similar result for (m, q)-isometries on Banach spaces is not true.
Permanent Link: http://hdl.handle.net/11104/0240468