arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2003.07416math.COmath.AC
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Cameron-Walker图的正则性和$h$ -多项式

The regularity and $h$-polynomial of Cameron-Walker graphs

Takayuki Hibi, Kyouko Kimura, Kazunori Matsuda, Adam Van Tuyl

摘要:

固定一个整数$n \geq 1$,并考虑$n \geq 1$顶点上的所有连通有限简单图的集合。对于该集合中的每个$G$,令$I(G)$表示多项式环$R = K[x_1,\ldots,x_n]$中的$G$的边理想。我们开始研究的集合$\mathcal{RD}(n) \subseteq \mathbb{N}^2$组成的所有对$(r,d)$在$r = {\rm reg}(R/I(G))$,Castelnuovo-Mumford正则性,和$d = {\rm deg} h_{R/I(G)}(t)$,$h$ -多项式的程度,因为我们改变了所有的$n$顶点上的连接图。特别地,我们识别集合$A(n)$和$B(n)$,使得$A(n) \subseteq \mathcal{RD}(n) \subseteq B(n)$。当我们限制在$n$顶点上的Cameron-Walker图族时,我们可以完全刻画所有可能的$(r,d)$ .

英文摘要:

Fix an integer $n \geq 1$, and consider the set of all connected finite simple graphs on $n$ vertices. For each $G$ in this set, let $I(G)$ denote the edge ideal of $G$ in the polynomial ring $R = K[x_1,\ldots,x_n]$. We initiate a study of the set $\mathcal{RD}(n) \subseteq \mathbb{N}^2$ consisting of all the pairs $(r,d)$ where $r = {\rm reg}(R/I(G))$, the Castelnuovo-Mumford regularity, and $d = {\rm deg} h_{R/I(G)}(t)$, the degree of the $h$-polynomial, as we vary over all the connected graphs on $n$ vertices. In particular, we identify sets $A(n)$ and $B(n)$ such that $A(n) \subseteq \mathcal{RD}(n) \subseteq B(n)$. When we restrict to the family of Cameron-Walker graphs on $n$ vertices, we can completely characterize all the possible $(r,d)$.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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