Valentin A.Zagrebnov
Quasi-Sectorial Contractions
(41K, LaTeX 2e with 1 PS figure)

ABSTRACT.  We revise the notion of the quasi-sectorial contractions. 
Our main theorem establishes a relation between semigroups of quasi-sectorial contractions and 
a class of m-sectorial generators. We discuss a relevance of this kind of contractions to 
the theory of operator-norm approximations of strongly continuous semigroups.