Abstract
If \(T=\left(\begin{array}{clcr}T_1&\quad C\\ 0&\quad T_2\end{array}\right) \in B(\mathcal{X }_1\oplus \mathcal{X }_2)\) is a Banach space upper triangular operator matrix with diagonal \((T_1, T_2)\) such that \(T_2\) is \(k\)-nilpotent for some integer \(k\ge 1\), then \(T\) inherits a number of its spectral properties, such as SVEP, Bishop’s property \((\beta )\) and the equality of Browder and Weyl spectrum, from those of \(T_1\). This paper studies such operators. The conclusions are then applied to provide a general framework for results pertaining (for example) to Browder, Weyl type theorems and supercyclicity for classes of Hilbert space operators, such as \(k\)-quasi hyponormal, \(k\)-quasi isometric and \(k\)-quasi paranormal operators, defined by a positivity condition.
Similar content being viewed by others
References
Aiena, P.: Fredholm and Local Spectral Theory with Applications to Multipliers. Kluwer, Dordrecht (2004)
Aiena, P., Chō, M., González, M.: Polaroid type operators under quasi-affinities. J. Math. Anal. Appl. 371, 485–495 (2010)
Aluthge, A., Wang, D.: An operator inequality which implies paranormality. Math. Inequal. Appl. 7, 113–119 (1999)
Amouch, M., Zguitti, H.: On the equivalence of Browder’s and generalized Browder’s theorem. Glasgow Math. J. 48, 179–185 (2006)
Bayart, F., Matheron, E.: Hyponormal operators, weighted shifts and weak forms of supercyclicity. Proc. Edinburgh Math. Soc. 49, 1–15 (2006)
Benhida, C., Zerouali, E.H.: Local spectral theory of linear operators \(RS\) and \(SR\). Integr. Equ. Oper. Theory 54, 1–8 (2006)
Campbell, S.L., Gupta, B.C.: On \(k\)-quasihyponormal operators. Math. Japonica 23, 185–189 (1978)
Duggal, B.P.: On characterising contractions with \(C_{10}\) pure part. Integr. Equ. Oper. Theory 27, 314–323 (1997)
Duggal, B.P.: SVEP, Browder and Weyl Theorems, Tópicas de Theoría de la Approximación III. In: Jiménez Pozo, M.A., Bustamante Gonzalez, J.P., Djordjević, S.V. (eds.) Textos Cientifficos BUAP Puebla, pp. 107–146 (2009) (freely available at http://www.fcfm.buap.mx/CA/analysis-mat/pdf/LIBRO_-TOP_-T_-APPROX.pdf)
Duggal, B.P., Djordjević, S.V., Kubrusly, C.S.: Hereditarily normaloid contractions. Acta Sci. Math. (Szeged) 71, 337–352 (2005)
Duggal, B.P., Jeon, I.H.: On \(p\)-quasihyponormal operators. Linear Algebra Appl. 420, 331–340 (2007)
Duggal, B.P., Jeon, I.H., Kim, I.H.: On \(*\)-paranormal contractions and properties of \(*\)-class operators. Linear Algebra Appl. 436, 954–962 (2012)
Duggal, B.P., Jeon, I.H., Kim, I.H.: On quasi-class \(A\) contractions. Linear Algebra Appl. 436, 3562–3567 (2012)
Duggal, B.P., Kubrusly, C.S.: Quasi-similar \(k\)-paranormal operators. Oper. Matrices 5, 417–423 (2011)
Eschmeier, J., Putinar, M.: Bishop’s condition \((\beta )\) and rich extensions of linear operators. Indiana Univ. Math. J. 37, 325–348 (1988)
Feldman, N.S., Miller, V.G., Miller, T.L.: Hypercyclic and supercyclic cohyponormal operators. Acta Sci. Math. (Szeged) 68, 303–328 (2002)
Furuta, T.: Invitation to Linear Operators. Taylor and Francis, London (2001)
Heuser, H.G.: Functional Analysis. Wiley, New York (1982)
Kim, I.H.: On \((p, k)\)-quasihyponormal operators. Math. Inequal. Appl. 7, 629–638 (2004)
Kubrusly, C.S., Duggal, B.P.: A note on \(k\)-paranormal operators. Oper. Matrices 4, 213–223 (2010)
Laursen, K.B., Neumann, M.M.: Introduction to Local Spectral Theory. Clarendon Press, Oxford (2000)
Mbekhta, M., Müller, V.: On the axiomatic theory of the spectrum II. Studia Math. 119, 129–147 (1996)
Müller, V.: Spectral Theory of Linear Operators, Operator Theory Advances and Applications, vol. 139. Birkhäuser Verlag (2003)
Suciu, L., Suciu, N.: Ergodic conditions and spectral properties for \(A\)-contractions. Opuscula Math. 28, 195–216 (2008)
Taylor, A.E., Lay, D.C.: Introduction to Functional Analysis. Wiley, New York (1980)
Yuan, J.T., Ji, G.X.: On \((n, k)\)-quasi paranormal operators. Studia Math. 209, 289–301 (2012)
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Duggal, B.P. Upper triangular matrix operators with diagonal \((T_1,T_2)\), \(T_2\) \(k\)-nilpotent. Rend. Circ. Mat. Palermo 62, 215–226 (2013). https://doi.org/10.1007/s12215-013-0104-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s12215-013-0104-z
Keywords
- Hilbert space
- \(k\) Quasi \(p\)-hyponormal
- \(M\)-hyponormal
- Paranormal
- \(*\)-Paranormal operators
- Browder and Weyl theorems
- Supercyclicity