The isomorphism problem for complete pick algebras: A survey

Complete Pick algebras -these are, roughly, the multiplier algebras in which Pick’s interpolation theorem holds true -have been the focus of much research in the last twenty years or so. All (irreducible) complete Pick algebras may be realized concretely as the algebras obtained by restricting multipliers on Drury-Arveson space to a subvariety of the unit ball; to be precise: every irreducible complete Pick algebra has the form [Formula presented] where M_d denotes the multiplier algebra of the Drury-Arveson space [Formula presented], and V is the joint zero set of some functions in M_d. In recent years several works were devoted to the classification of complete Pick algebras in terms of the complex geometry of the varieties with which they are associated. The purpose of this survey is to give an account of this research in a comprehensive and unified way. We describe the array of tools and methods that were developed for this program, and take the opportunity to clarify, improve, and correct some parts of the literature.