English

A solution to Itoh's conjecture for integral closure filtration

Commutative Algebra 2024-04-12 v1

Abstract

Let (A,m)(A,\mathfrak{m}) be an analytically unramified Cohen-Macaulay local ring of dimension d3d \geq 3 and let a\mathfrak{a} be an m\mathfrak{m}-primary ideal in AA. If II is an ideal in AA then let II^* be the integral closure of II in AA. Let Ga(A)=n0(an)/(an+1)G_{\mathfrak{a}}(A)^* = \bigoplus_{n\geq 0 }(\mathfrak{a}^n)^*/(\mathfrak{a}^{n+1})^* be the associated graded ring of the integral closure filtration of a\mathfrak{a}. Itoh conjectured in 1992 that if third Hilbert coefficient of Ga(A)G_{\mathfrak{a}}(A)^* , i.e., e3a(A)=0e_3^{\mathfrak{a}^*}(A) = 0 and AA is Gorenstein then Ga(A)G_{\mathfrak{a}}(A)^* is Cohen-Macaulay. In this paper we prove Itoh's conjecture (more generally for analytically unramified Cohen-Macaulay local rings).

Keywords

Cite

@article{arxiv.2404.07638,
  title  = {A solution to Itoh's conjecture for integral closure filtration},
  author = {Tony J. Puthenpurakal},
  journal= {arXiv preprint arXiv:2404.07638},
  year   = {2024}
}

Comments

arXiv admin note: substantial text overlap with arXiv:2205.10615

R2 v1 2026-06-28T15:50:57.164Z