ACTA issues

On power bounded operators that are quasiaffine transforms of singular unitaries

Maria F. Gamal'

Acta Sci. Math. (Szeged) 77:3-4(2011), 589-606
24/2010

Abstract. In [9] a question is raised: if a power bounded operator is quasisimilar to a singular unitary operator, is it similar to this unitary operator? For polynomially bounded operators, a positive answer to this question is known [1], [13]. In this paper a positive answer is given in some particular cases, but in general an answer rests unknown.


AMS Subject Classification (1991): 47A05, 47B99, 47B15

Keyword(s): power bounded operator, singular unitary operator, similarity, quasisimilarity, quasiaffine transform


Received April 8, 2010, and in revised form October 12, 2010. (Registered under 24/2010.)