Department of Mathematics, Tianjin University, Tianjin 300072, China; LiuHui Center for Applied Mathematics, Nankai University and Tianjin University, Tianjin 300072, China
Abstract:
Let Un be the unit polydisc of Cn and φ = (φ1,...,φn) a holomorphic self-map of Un. Let 0 ≤α 1. This paper shows that the composition operator C is bounded on the Lipschitz space Lip(Un) if and only if there exists M > 0 such that
for z ∈ Un. Moreover Cφ is compact on Lipα(Un) if and only if Cφ is bounded on Lipα(Un) and for every ε>0, there exists a δ > 0 such that