Searcharxiv⌕ Search

arXiv · 2610.02767

Almost Gorenstein standard graded rings and their localizations

Abstract

We prove that a Cohen-Macaulay standard graded integral domain over a field is almost Gorenstein as a graded ring if and only if the completion of its localization at the graded maximal ideal is almost Gorenstein as a local ring.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Naoki Endo. 2026-10-02. Almost Gorenstein standard graded rings and their localizations. https://arxiv.org/abs/2610.02767

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

Comprehensive Restriction Algorithm for Hypergeometric Systems

An algorithm computing the restriction of a holonomic D-module to a linear subspace was given by T.Oaku in 1997. We consider a problem of computing the restriction for a given holonomic D-module with parameters. We will give a partial answer to the problem for general holonomic D-modules and an answer to hypergeometric holonomic D-modules. The above results are based on comprehensive Groebner system and an algorithm for the isomorphic classification of hypergeometric D-modules.

math.AC↗

Trace ideals of exterior powers of the module of differentials

For each $i \geq 0$, we study the trace ideal of the $i$-th exterior power of the module of differentials. In characteristic zero, we show that these ideals characterize the polynomial rank of graded rings and the formal power series rank of complete local rings with finite residue-field extension, namely the maximal number of variables for a polynomial or formal power series extension over a subring. Moreover, we introduce the top differential trace and prove that it precisely defines the singular locus of reduced equidimensional local or graded rings. Motivated by this, we introduce and investigate nearly regular rings, which are rings whose top differential trace contains the maximal ideal.

math.AC↗

A palindromicity criterion for the $h$-polynomials of bipartite edge rings

We study a symmetry problem for the $h$-polynomials of edge rings of bipartite graphs. Let $G$ be a bipartite graph and write $h(\mathbb{k}[G];t)=h_0+h_1t+\cdots+h_st^s$. We prove that if $\Bbbk[G]$ is pseudo-Gorenstein and $h_1=h_{s-1}$, then $\Bbbk[G]$ is Gorenstein. Equivalently, under these assumptions the $h$-polynomial of $\Bbbk[G]$ is palindromic. The proof treats the $2$-connected case first by translating the numerical condition $h_1=h_{s-1}$ into a tight-separation condition for non-edges, and then passes to arbitrary bipartite graphs using the block decomposition. We also construct a blockwise minimal Gorenstein closure, obtained by adjoining all non-edges not separated by tight acceptable sets, and show that this construction preserves the next-to-leading coefficient of the $h$-polynomial.

math.AC↗