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arXiv 2408.00745math.CO
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拟阵的Chow环与增广Chow环的等变$\gamma$-正性

Equivariant $γ$-positivity of Chow rings and augmented Chow rings of matroids

Hsin-Chieh Liao

AI总结:

本研究证明拟阵的Chow环与增广Chow环具有等变$\gamma$-正性,验证了相关猜想,给出展开系数显式解释,推广了均匀拟阵等变正性及拟对称函数正性的已有结果,并解答了二项式欧拉多项式展开的相关问题。

摘要:

本文证明了拟阵的Chow环与增广Chow环在拟阵任意自同构群的作用下具有等变$\gamma$-正性,验证了Angarone、Nathanson和Reiner提出的一个猜想。我们的方法对等变$\gamma$-展开的系数给出了显式解释。将定理应用于均匀拟阵(uniform matroids),我们推广并复原了两类已知结果:一是作者此前工作中关于均匀拟阵等变Charney-Davis量正性的结论,二是由Shareshian和Wachs首次证明的欧拉与二项式欧拉拟对称函数的Schur-$\gamma$-正性。最后,我们解答了Athanasiadis提出的关于推广二项式欧拉多项式$\gamma$-展开的问题。

英文摘要:

In this paper, we prove the Chow ring and augmented Chow ring of a matroid is equivariant $γ$-positivity under the action of any group of automorphisms of the matroid. This verifies a conjecture of Angarone, Nathanson, and Reiner. Our method gives an explicit interpretation to the coefficients of the equivariant $γ$-expansion. Applying our theorem to uniform matroids, we extend and recover known results regarding the positivity of the equivariant Charney-Davis quantity of uniform matroids in the author's previous work and the Schur-$γ$-positivity of Eulerian and binomial Eulerian quasisymmetric functions first proved by Shareshian and Wachs. In the end, we answer a problem proposed by Athanasiadis about extending the $γ$-expansion of the binomial Eulerian polynomial.

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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