arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2209.06752math.AGmath.CO
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带符号排列多面体、delta-拟阵及其他

Signed permutohedra, delta-matroids, and beyond

Christopher Eur, Alex Fink, Matt Larson, Hunter Spink

AI总结:

本文建立了B型排列多面体环面簇的代数几何与delta-拟阵组合学的联系,计算了B型广义排列多面体的体积和格点计数,并利用热带Hodge理论确立了包含可实现delta-拟阵在内的该类拟阵的类Tutte不变量的对数凹性。

摘要:

我们建立了B型排列多面体环面簇的代数几何与delta-拟阵组合学之间的联系。利用这一联系,我们计算了B型广义排列多面体的体积和格点计数。将热带Hodge理论应用于“delta-拟阵的示性类”的新框架(该框架仿照与可实现delta-拟阵相关的某些向量丛构建),我们确立了一大类delta-拟阵(包含所有可实现delta-拟阵)的类Tutte不变量的对数凹性。我们的结果包含了对所有(普通)拟阵的新的对数凹性命题作为特例。

英文摘要:

We establish a connection between the algebraic geometry of the type B permutohedral toric variety and the combinatorics of delta-matroids. Using this connection, we compute the volume and lattice point counts of type B generalized permutohedra. Applying tropical Hodge theory to a new framework of "tautological classes of delta-matroids," modeled after certain vector bundles associated to realizable delta-matroids, we establish the log-concavity of a Tutte-like invariant for a broad family of delta-matroids that includes all realizable delta-matroids. Our results include new log-concavity statements for all (ordinary) matroids as special cases.

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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