Eungil Ko and Ji Eun Lee Ewha Women's University, Ewha Women's University
Abstract : In this paper we study some properties of rank one perturbations of the unilateral shift operators $T=S+ u\otimes v$. In particular, we give some criteria for eigenvalues of $T$. Also we characterize some conditions for $T$ to be hyponormal.
Keywords : rank one perturbation, the unilateral shift and hyponormal operator