In this paper,we show that the hyponormal Toeplitz operator T with trigonometric polynomial symbol is either normal or completely non-normal.Moreover,if T is non-normal,then Tˉ has a dense set of cyclic vectors.Some general conditions are also considered.
机构:
Stanford Univ, Dept Hlth Res & Policy, Div Epidemiol, Stanford, CA 94305 USAStanford Univ, Dept Hlth Res & Policy, Div Epidemiol, Stanford, CA 94305 USA