On generators of -semigroups of composition operators
arXiv:1708.02259 · doi:10.1007/s11856-018-1815-9
Abstract
Avicou, Chalendar and Partington proved that an (unbounded) operator on the classical Hardy space generates a semigroup of composition operators if and only if it generates a quasicontractive semigroup. Here we prove that if such an operator generates a semigroup, then it is automatically a semigroup of composition operators, so that the condition of quasicontractivity of the semigroup in the cited result is not necessary. Our result applies to a rather general class of Banach spaces of analytic functions in the unit disc.