arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1706.09002math.ACmath.CO
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正则性的二项式边理想$3$

Binomial edge ideals of regularity $3$

Sara Saeedi Madani, Dariush Kiani

摘要:

设$J_G$是图$G$的二项式边理想.我们刻画了所有图的二项式边理想,以及他们的初始理想,有正则性$3$。因此,我们刻画了所有图$G$,使得$J_G$是极值Gorenstein。事实上,这些特征的后果,我们得到的一个明确的公式的正则性二项式边理想的两个图的连接产品。最后,利用我们的正则性公式,讨论了文献中的一些公开问题。特别是我们反驳了\cite{CDI}中关于弱闭图的正则性的一个猜想。

英文摘要:

Let $J_G$ be the binomial edge ideal of a graph $G$. We characterize all graphs whose binomial edge ideals, as well as their initial ideals, have regularity $3$. Consequently we characterize all graphs $G$ such that $J_G$ is extremal Gorenstein. Indeed, these characterizations are consequences of an explicit formula we obtain for the regularity of the binomial edge ideal of the join product of two graphs. Finally, by using our regularity formula, we discuss some open problems in the literature. In particular we disprove a conjecture in \cite{CDI} on the regularity of weakly closed graphs.

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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