Poincaré series of modules over compressed Gorenstein local rings
arXiv:1211.6514
Abstract
Given positive integers e and s we consider Gorenstein Artinian local rings R of embedding dimension e whose maximal ideal satisfies . We say that R is a compressed Gorenstein local ring when it has maximal length among such rings. It is known that generic Gorenstein Artinian algebras are compressed. If , we prove that the Poincare series of all finitely generated modules over a compressed Gorenstein local ring are rational, sharing a common denominator. A formula for the denominator is given. When s is even this formula depends only on the integers e and s. Note that for examples of compressed Gorenstein local rings with transcendental Poincare series exist, due to Bøgvad.
revised version, to appear in Adv. Math