arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1507.03221math.COmath.AC
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由序多面体和链多面体生成的Gorenstein Fano多面体

Gorenstein Fano polytopes arising from order polytopes and chain polytopes

Takayuki Hibi, Kazunori Matsuda, Akiyoshi Tsuchiya

摘要:

Richard Stanley引入了由有限偏序集$P$生成的序多面体$\mathcal{O}(P)$和链多面体$\mathcal{C}(P)$,并证明了$\mathcal{O}(P)$的Ehrhart多项式与$\mathcal{C}(P)$的Ehrhart多项式相等.此外,第一作者和李南研究了$\mathcal{O}(P)$和$\mathcal{C}(P)$的么模等价问题.本文研究了三个整凸多胞体$Γ(\mathcal{O}(P), -\mathcal{O}(Q))$,$Γ(\mathcal{O}(P), -\mathcal{C}(Q))$和$Γ(\mathcal{C}(P), -\mathcal{C}(Q))$,其中$P$和$Q$是具有$| P | = | Q |$的偏序集.首先,将表明$Γ(\mathcal{O}(P), -\mathcal{C}(Q))$的Ehrhart多项式与$Γ(\mathcal{C}(P), -\mathcal{C}(Q))$的Ehrhart多项式一致。当$P$和$Q$具有共同的线性扩张时,证明了这三个凸多胞体具有相同的Ehrhart多项式.其次,解决了偏序集$P$和$Q$的特征问题,使得$Γ(\mathcal{O}(P), -\mathcal{O}(Q))$或$Γ(\mathcal{O}(P), -\mathcal{C}(Q))$或$Γ(\mathcal{C}(P), -\mathcal{C}(Q))$是光滑的Fano多面体.最后,当这三个多面体是光滑的Fano多面体时,讨论了这三个多面体的幺模等价问题。

英文摘要:

Richard Stanley introduced the order polytope $\mathcal{O}(P)$ and the chain polytope $\mathcal{C}(P)$ arising from a finite partially ordered set $P$, and showed that the Ehrhart polynomial of $\mathcal{O}(P)$ is equal to that of $\mathcal{C}(P)$. In addition, the unimodular equivalence problem of $\mathcal{O}(P)$ and $\mathcal{C}(P)$ was studied by the first author and Nan Li. In the present paper, three integral convex polytopes $Γ(\mathcal{O}(P), -\mathcal{O}(Q))$, $Γ(\mathcal{O}(P), -\mathcal{C}(Q))$ and $Γ(\mathcal{C}(P), -\mathcal{C}(Q))$, where $P$ and $Q$ are partially ordered sets with $| P | = | Q |$, will be studied. First, it will be shown that the Ehrhart polynomial of $Γ(\mathcal{O}(P), -\mathcal{C}(Q))$ coincides with that of $Γ(\mathcal{C}(P), -\mathcal{C}(Q))$. Furthermore, when $P$ and $Q$ possess a common linear extension, it will be proved that these three convex polytopes have the same Ehrhart polynomial. Second, the problem of characterizing partially ordered sets $P$ and $Q$ for which $Γ(\mathcal{O}(P), -\mathcal{O}(Q))$ or $Γ(\mathcal{O}(P), -\mathcal{C}(Q))$ or $Γ(\mathcal{C}(P), -\mathcal{C}(Q))$ is a smooth Fano polytope will be solved. Finally, when these three polytopes are smooth Fano polytopes, the unimodular equivalence problem of these three polytopes will be discussed.

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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