Hyperexpansive composition operators

  title={Hyperexpansive composition operators},
  author={Zenon J. Jablonski},
The notion of a completely hyperexpansive operator has been introduced in [ 2 ] by Athavale. In this paper bounded and unbounded hyperexpansive composition operators are investigated. A unique semispectral measure is associated with a bounded completely hyperexpansive composition operator. Examples of bounded and unbounded densely defined $2$ -isometric (completely hyperexpansive, $2$ -hyperexpansive) composition operators with invariant domains are given.