TY  - JOUR
AU  - Rashid, M.H.M. 
AU  - Noorani, M.S.M. 
AU  - Saari, A.S. 
PY  - 2008
TI  - Weyl's Type Theorems for Quasi-Class A Operators
JF  - Journal of Mathematics and Statistics
VL  - 4
IS  - 2
DO  - 10.3844/jmssp.2008.70.74
UR  - https://thescipub.com/abstract/jmssp.2008.70.74
AB  - A variant of Weyl theorem for a class of quasi-class A acting on an infinite complex Hilbert space were discussed.  If the adjoint of T is a quasi-class A operator, then the generalized a-Weyl holds for f(T) , for every function that analytic on the spectrum of T. The generalized Weyl theorem holds for a quasi-class A was proved. Also, a characterization of the Hilbert space as a direct sum of range and kernel of a quasi-class A was given. Among other things, if the operator is a quasi-class A, then the B-Weyl spectrum satisfies the spectral theorem was characterized.