Complete Nevanlinna-Pick property of Dirichlet-type spaces
We prove that all Dirichlet-type spaces of functions analytic in the unit disk whose derivatives are square area integrable with superharmonic weights have complete Nevanlinna-Pick reproducing kernels. As a corollary, we obtain a commutant lifting theorem for cyclic analytic two-isometries. (C) 2002 Elsevier Science (USA).