English

Homological dimensions of Burch ideals, submodules and quotients

Commutative Algebra 2024-03-04 v3

Abstract

The notion of Burch ideals and Burch submodules were introduced (and studied) by Dao-Kobayashi-Takahashi in 2020 and Dey-Kobayashi in 2022 respectively. The aim of this article is to characterize various local rings in terms of homological invariants of Burch ideals, Burch submodules, or that of the corresponding quotients. Specific applications of our results include the following: Let (R,m)(R,\mathfrak{m}) be a commutative Noetherian local ring. Let M=IM=I be an integrally closed ideal of RR such that depth(R/I)=0{\rm depth}(R/I)=0, or M=mN0M = \mathfrak{m} N \neq 0 for some submodule NN of a finitely generated RR-module LL such that either depth(N)1{\rm depth}(N)\ge 1 or LL is free. It is shown that: (1) II has maximal projective ((resp., injective)) complexity and curvature. (2) RR is Gorenstein if and only if ExtRn(M,R)=0{\rm Ext}_R^n(M,R)=0 for any three consecutive values of nmax{depth(R)1,0}n \ge \max\{{\rm depth}(R)-1,0\}. (3) RR is CM (Cohen-Macaulay) if and only if CM-dimR(M)\dim_R(M) is finite.

Keywords

Cite

@article{arxiv.2212.07418,
  title  = {Homological dimensions of Burch ideals, submodules and quotients},
  author = {Dipankar Ghosh and Aniruddha Saha},
  journal= {arXiv preprint arXiv:2212.07418},
  year   = {2024}
}

Comments

14 pages, Journal of Pure and Applied Algebra (to appear), Revised version, Particularly added Remark 2.9 and its proof, and paragraph 4.9