Properties of m-complex symmetric operators
DOI:
https://doi.org/10.24193/subbmath.2017.2.09Keywords:
Conjugation, $m$-Complex symmetric operator, Nilpotent perturbations, Decomposable, Weyl type theoremsAbstract
In this paper, we study several properties of $m$-complex symmetric operators. In particular,
we prove that if $T\in{\cal L(H)}$ is an $m$-complex symmetric operator and $N$ is a nilpotent operator of order $n>2$ with $TN=NT$, then $T+N$ is a $(2n+m-2)$-complex symmetric operator. Moreover, we investigate the decomposability of $T+A$ and $TA$ where $T$ is an $m$-complex symmetric operator and $A$ is an algebraic operator. Finally, we provide various spectral relations of such operators.
As some applications of these results, we discuss Weyl type theorems for such operators.
References
bibitem{Ai} P. Aiena, {it Fredholm and local spectral theory with applications to multipliers}, Kluwer Academic Pub. 2004.
bibitem{Ag} J. Agler, {it Sub-Jordan operators: Bishop's theorem, spectral inclusion, and spectral sets}, J. Oper. Theory {bf 7}(2) (1982) 373-395.
bibitem{ACG}P. Aiena, M. L. Colasante, and M. Gonz'{a}lez, {it Operators which have a closed quasi-nilpotent part}, Proc. Amer. Math. Soc. {bf 130}(2002), 2701-2710.
bibitem{AZ} M. Amouch and H. Zguitti, {it On the equivalence of Browder's and generalized Browder's theorem}, Glasgow Math. J. {bf 48}(2006), 179-185.
bibitem{BK} M. Berkani and J. J. Koliha, {it Weyl type theorems for bounded linear operators}, Acta Sci. Math. {bf 69}(2003), 359-376.
bibitem{BMMN} T. Berm'{u}dez, A. Martin'{o}n, V. M"{u}ller, and J. Noda, {it Perturbation of $m$-isometries by nilpotent operators}, Abstr. Appl. Anal. {bf 2}(2014), 313-328.
bibitem{Ber} M. Berkani, {it On a class of quasi-Fredholm operators}, Int. Eq. Op. Th. {bf34}(1999), 244-249.
bibitem{COTU} M. Ch=o, S. Ota, K. Tanahashi, and M. Uchiyama, {it Spectral properties of $m$-isometric operators}, Functional Analysis, Application and Computation 4:2 (2012), 33-39.
bibitem{CKL} M. Ch=o, E. Ko, and J. Lee, {On $m$-complex symmetric operators}, Mediterranean Journal of Mathematics, in press (2015).
bibitem{CKL2} M. Ch=o, E. Ko, and J. Lee, {On $m$-complex symmetric operators} II, Mediterranean Journal of Mathematics, in press (2016).
bibitem{CF} I. Colojoara and C. Foias, {it Theory of generalized spectral operators}, Gordon and Breach, New York, 1968.
bibitem{Es} J. Eschmeier, {it Invariant subspaces for operators with Bishop's property ($beta$) and thick spectrum}, J. Funct. Anal. {bf 94}(1990), 196-222.
bibitem{Ga 1} S. R. Garcia, {it Aluthge transforms of complex symmetric operators and applications}, Int. Eq. Op. Th. {bf 60}(2008), 357-367.
bibitem{Ga 3} S. R. Garcia and M. Putinar, {it Complex symmetric operators and applications}, Trans. Amer. Math. Soc. {bf 358}(2006), 1285-1315.
bibitem{Ga 4} underline{hspace{2cm}}, {it Complex symmetric operators and applications} II, Trans. Amer. Math. Soc. {bf 359}(2007), 3913-3931.
bibitem{GW} S. R. Garcia and W. R. Wogen, {it Some new classes of complex symmetric operators}, Trans. Amer. Math. Soc. {bf 362}(2010), 6065-6077.
bibitem{Ha} P. R. Halmos, {it A Hilbert space problem book}, Springer-Verlag Berlin Heidelberg New York, 1980.
bibitem{He} J. W. Helton, {it Operators with a representation as multiplication by $x$ on a Sobolev space}, Colloquia Math. Soc. Janos Bolyai {bf 5}, Hilbert Space Operators, Tihany, Hungary (1970), 279-287.
bibitem{JKLL} S. Jung, E. Ko, M. Lee, and J. Lee, {it On local spectral properties of complex symmetric operators}, J. Math. Anal. Appl. {bf 379}(2011), 325-333.
bibitem{LN} K. Laursen and M. Neumann, {em An introduction to local spectral theory}, Clarendon Press, Oxford, 2000.
bibitem{MR} S. McCullough and L. Rodman, {it Hereditary classes of operators and matrices}, Amer. Math. Monthly, {bf 104}(5) (1997), 415-430.
Downloads
Additional Files
Published
Issue
Section
License
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Transfer of copyright agreement: When the article is accepted for publication, the authors and the representative of the coauthors, hereby agree to transfer to Studia Universitatis Babeș-Bolyai Mathematica all rights, including those pertaining to electronic forms and transmissions, under existing copyright laws, except for the following, which the authors specifically retain: the authors can use the material however they want as long as it fits the NC ND terms of the license. The authors have all rights for reuse according to the license.