| Popis: |
The aim of this paper is to study the Weyl type-theorems for the orthogonal direct sum S T, where S and T are bounded linear operators acting on a Banach space X. Among other results, we prove that if both T and S possesses property (gb) and if ( T) a(S), ( S) a(T), then S T possesses property (gb) if and only if SBF+ (S T) = SBF+ (S)( SBF+ (T). Moreover, we prove that if T and S both satises generalized Browder's theorem, then S T satises generalized Browder's theorem if and only if BW(S T) = BW(S) ( BW(T). |
