Composition operators between area-type Nevanlinna classes

Abstract

This paper is concerned with the composition operators between the area-type Nevanlinna classes. Some sufficient and necessary conditions are given in terms of the concept of Carleson measure and the standard techniques of Montel Theorem for the composition operator C_Ψ: N_a^p → N_a^q to be bounded or compact, where 1 < p "d q. Moreover, the inducing maps which induce invertible or Fredholm composition operators on N_a^p are characterized.