A remark on sequentially Cohen-Macaulay monomial ideals

TL;DR

This paper characterizes when connected graphs with a basic 5-cycle are sequentially Cohen-Macaulay based on shedding vertices and explores the properties of square-free monomial ideals related to this class.

Contribution

It provides a new criterion for sequentially Cohen-Macaulay graphs with a 5-cycle using shedding vertices and investigates their algebraic properties.

Findings

Characterization of sequentially Cohen-Macaulay graphs with a 5-cycle

Conditions involving shedding vertices for Cohen-Macaulayness

Analysis of Castelnuovo-Mumford regularity for specific monomial ideals

Abstract

Let $R=K[x_1,\ldots,x_n]$ be the polynomial ring in $n$ variables over a field $K$. We show that if $G$ is a connected graph with a basic $5$-cycle $C$, then $G$ is a sequentially Cohen-Macaulay graph if and only if there exists a shedding vertex $x$ of $C$ such that $G\setminus x$ and $G\setminus N[x]$ are sequentially Cohen-Macaulay graphs. Furthermore, we study the sequentially Cohen-Macaulay and Castelnuovo-Mumford regularity of square-free monomial ideals in some special cases.