Abstract
This work proves that if T belong to the class M-A(n*) operator and S* is an invertible operator belonging to the same class such that TX=XS, then T*X=XS*, where X is a Hilbert-Schmidt operator.
Keywords
- Hilbert space
- Fuglede-Putman
- A(n*) operators
- 1- Introduction: Let π» denote a separable complex Hilbert space characterized by the inner product <β
- β>
References
- Berberian, S.K. Extensions of a theorem of Fuglede and Putnam. Proc. Am. Math. Soc. 71, 113β114 (1978).
- Braha N., Lohaj M., Marevci F. and Lohaj Sh., Some properties of paranormal and hyponormal operators, Bull. Math. Anal. Appl., V.1, Issue 2,23β35 (2009).
- Conway, J.B. Subnormal operators. Research notes in mathematics, 5, Pitman advanced pub. program, (1981).
- Dugall B.P., Jeon I.H. and Kim I.H., On β-paranormal contractions and properties for β-class A operators, Linear Alg. Appl. 436, 954β962, (2012).
- Furuta T., On the Class of Paranormal Operators, Proc. Jap. Acad. 43(1967), 594-59
- Kaplansky, I. Products of normal operators. Duke Math. J. 20(2), 257β260 (1953).
- Laursen K.B., Operators with finite ascent, Pacific J. Math. 152, 323β336, (1992).
- Mecheri S., On quasi-β-paranormal operators, Ann. Funct. Anal 3,86β91, (2012).
- Mecheri.S and Makhlouf.S, Weyl Type theorems for posinormal operators, Math. Proc. Royal Irish. Acad. 108, no.1, 68β79, (2008).
- Panayappan.S and Radharamani. A, A Note on p-β-paranormal Operators and Absolute k β -Paranormal Operators, Int. J. Math. Anal. 2, no. 25-28, 1257β1261, (2008)
- Yuan, J.T., Wang, C.H. FugledeβPutnam type theorems for (p, k)-quasihyponormal operators via hyponormal operators. J. Inequal. Appl. 2019, Article ID 122 (2019).