Skip to content

On vanishing of certain Ext modules

Shiro Goto, Futoshi Hayasaka, Ryo Takahashi

math.ACarXiv:math/0701195

Abstract

Let R be a Noetherian local ring with the maximal ideal m and dim R=1. In this paper, we shall prove that the module Ext1R(R/Q,R) does not vanish for every parameter ideal Q in R, if the embedding dimension v(R) of R is at most 4 and the ideal m2 kills the 0th local cohomology module Hm0(R). The assertion is no longer true unless v(R) ≤ 4. Counterexamples are given. We shall also discuss the relation between our counterexamples and a problem on modules of finite G-dimension.

Create a lesson