A linear formula for the generalized multiplicity sequence
Commutative Algebra
2012-11-15 v1
Abstract
For an arbitrary ideal I in a local ring R and a finitely generated R-module M, we prove a formula expressing each generalized multiplicity sequence c_k(I,M) as a linear combination of certain local multiplicities. As a consequence, when M is formally equidimensional, we prove that if I is contained in J and c_k(I,M)=c_k(J,M) for all k, then I is a reduction of (J,M). The converse of this statement is also known to be true by a result of Ciuperca. This theorem gives a complete numerical characterization of the integral closure, generalizing a well known theorem of Rees.
Cite
@article{arxiv.1211.3192,
title = {A linear formula for the generalized multiplicity sequence},
author = {Thomas Dunn},
journal= {arXiv preprint arXiv:1211.3192},
year = {2012}
}