ACTA issues

## Composition operators similar to contractions

Valentin Matache

Acta Sci. Math. (Szeged) 85:3-4(2019), 561-571
78/2018

 Abstract. Operators of type $f\to f\circ \varphi$ acting on function spaces are called composition operators. We consider composition operators acting on the Hilbert Hardy space on the open unit disc or the right half-plane, study when they are similar to contractions, and obtain results interesting from the point of view of dilation theory of contractions and function theory. DOI: 10.14232/actasm-018-578-9 AMS Subject Classification (1991): 47B33, 47A45 Keyword(s): composition operators, contractions Received August 24, 2018 and in final form December 14, 2018. (Registered under 78/2018.)