Generalized a-Weyl's theorem for direct sums


Anuradha Gupta, Neeru Kashyap




If $T$ and $S$ are Hilbert space operators obeying generalized a-Weyl's theorem, then it does not necessarily imply that the direct sum $T\oplus S$ obeys generalized a-Weyl's theorem. In this paper we explore certain conditions on $T$ and $S$ so that the direct sum $T\oplus S$ obeys generalized a-Weyl's theorem.