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Related papers: Ulrich ideals and almost Gorenstein rings

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Motivated by the definition of nearly Gorenstein rings, we introduce the notion of full-trace modules over commutative Noetherian local rings--namely, finitely generated modules whose trace equals the maximal ideal. We investigate the…

Commutative Algebra · Mathematics 2025-05-22 Ela Celikbas , Olgur Celikbas , Jürgen Herzog , Shinya Kumashiro

Quasi-socle ideals, that is the ideals $I$ of the form $I= Q : \mathfrak{m}^q$ in Gorenstein numerical semigroup rings over fields are explored, where $Q$ is a parameter ideal, and $\mathfrak{m}$ is the maximal ideal in the base local ring,…

Commutative Algebra · Mathematics 2008-01-17 Shiro Goto , Satoru Kimura , Naoyuki Matsuoka

We analyze whether Ulrich modules, not necessarily maximal CM (Cohen-Macaulay), can be used as test modules, which detect finite homological dimensions of modules. We prove that Ulrich modules over CM local rings have maximal complexity and…

Commutative Algebra · Mathematics 2023-10-18 Souvik Dey , Dipankar Ghosh

Ulrich ideals in numerical semigroup rings of small multiplicity are studied. If the semigroups are three-generated but not symmetric, the semigroup rings are Golod, since the Betti numbers of the residue class fields of the semigroup rings…

Commutative Algebra · Mathematics 2021-11-02 Naoki Endo , Shiro Goto

The notion of almost Gorenstein ring given by Barucci and Fr{\"o}berg \cite{BF} in the case where the local rings are analytically unramified is generalized, so that it works well also in the case where the rings are analytically ramified.…

Commutative Algebra · Mathematics 2011-06-09 Shiro Goto , Naoyuki Matsuoka , Tran Thi Phuong

Let R be a Cohen-Macaulay local ring possessing a canonical module. In this paper we consider when the maximal ideal of R is self-dual, i.e. it is isomorphic to its canonical dual as an R-module. local rings satisfying this condition are…

Commutative Algebra · Mathematics 2020-10-21 Toshinori Kobayashi

We investigate the existence of ideals $I$ in a one-dimensional Gorenstein local ring $R$ satisfying $\mathrm{Ext}^{1}_{R}(I,I)=0$.

Commutative Algebra · Mathematics 2018-04-04 Craig Huneke , Srikanth B. Iyengar. , Roger Wiegand

The Ulrich ideals in the semigroup rings $k[[t^5, t^{11}]]$ and $k[[t^5,t^6,t^9]]$ are determined, by describing the normal forms of systems of generators, where $k[[t]]$ denotes the formal power series ring over a field $k$.

Commutative Algebra · Mathematics 2021-11-02 Naoki Endo , Shiro Goto , Shin-ichiro Iai , Naoyuki Matsuoka

We study reflexive ideals in one-dimensional Cohen-Macaulay local rings, providing characterizations of almost Gorenstein rings, rings with minimal multiplicity, and Arf rings, which describe their reflexive fractional ideals.

Commutative Algebra · Mathematics 2025-06-17 Pietro Campochiaro , Marco D'Anna , Francesco Strazzanti

For a Cohen-Macaulay local ring $(R,\mathfrak{m})$ with canonical module, we study how relations between $\text{index}(R)$ and $\text{g}\ell\ell(R)$ and between $\text{index}(R)$ and $e(R)$ are preserved when factoring out regular sequences…

Commutative Algebra · Mathematics 2024-10-16 Richard F. Bartels

In this paper, we introduce an invariant of Cohen-Macaulay local rings in terms of the reduction number of canonical ideals. The invariant can be defined in arbitrary Cohen-Macaulay rings and it measures how close to being Gorenstein.…

Commutative Algebra · Mathematics 2022-01-26 Shinya Kumashiro

Quasi-socle ideals, that is the ideals $I$ of the form $I= Q : \mathfrak{m}^q$ in a Noetherian local ring $(A, \mathfrak{m})$ with the Gorenstein tangent cone $\mathrm{G}(\mathfrak{m}) = \bigoplus_{n \geq…

Commutative Algebra · Mathematics 2008-07-29 Shiro Goto , Satou Kimura , Naoyuki Matsuoka , Tran Thi Phuong

The purpose of this article is to provide a new characterization of Cohen-Macaulay local rings. As a consequence we deduce that a local (Noetherian) ring $R$ is Gorenstein if and only if every parameter ideal of $R$ is irreducible.

Commutative Algebra · Mathematics 2013-08-29 Kamal Bahmanpour , Reza Naghipour

The Auslander-Reiten conjecture is a notorious open problem about the vanishing of Ext modules. In a Cohen-Macaulay complete local ring $R$ with a parameter ideal $Q$, the Auslander-Reiten conjecture holds for $R$ if and only if it holds…

Commutative Algebra · Mathematics 2023-03-21 Shinya Kumashiro

The Cohen-Macaulay type of idealizations of maximal Cohen-Macaulay modules over Cohen-Macaulay local rings is explored. There are two extremal cases, one of which is closely related to the theory of Ulrich modules \cite{BHU, GOTWY1, GOTWY2,…

Commutative Algebra · Mathematics 2018-04-24 Shiro Goto , Shinya Kumashiro , Nguyen Thi Hong Loan

Let I be an m-primary ideal of a Noetherian local ring (R,m). We consider the Gorenstein and complete intersection properties of the associated graded ring G(I) and the fiber cone F(I) of I as reflected in their defining ideals as…

Commutative Algebra · Mathematics 2007-05-23 William Heinzer , Mee-Kyoung Kim , Bernd Ulrich

In the present paper we investigate a question stemming from a long-standing conjecture of Vasconcelos: given a generically a complete intersection perfect ideal I in a regular local ring R, is it true that if I/I^2 (or R/I^2) is…

Commutative Algebra · Mathematics 2011-04-19 Paolo Mantero , Yu Xie

We study finitely generated modules of minimal multiplicity, a notion introduced by Puthenpurakal that extends the classical concept of minimal multiplicity from rings to modules. Our main result characterizes when trace ideals or reflexive…

Commutative Algebra · Mathematics 2026-02-10 Ela Celikbas , Olgur Celikbas , Naoki Endo , Shinya Kumashiro

Given a Noetherian local ring (R,m) it is shown that there exists an integer l such that R is Gorenstein if and only if some system of parameters contained in m^l generates an irreducible ideal. We obtain as a corollary that R is Gorenstein…

Commutative Algebra · Mathematics 2007-05-23 Thomas Marley , Mark W. Rogers , Hideto Sakurai

Let $H\subseteq \mathbb{N}^d$ be a normal affine semigroup, $R=K[H]$ its semigroup ring over the field $K$ and $\omega_R$ its canonical module. The Ulrich elements for $H$ are those $h$ in $H$ such that for the multiplication map by…

Commutative Algebra · Mathematics 2021-01-22 Jürgen Herzog , Raheleh Jafari , Dumitru I. Stamate