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arXiv 0908.1284math.COmath.RT
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Kerov多项式的一个新的显式公式

A new explicit formula for Kerov polynomials

P. Petrullo, D. Senato

摘要:

我们证明了一个公式表示的Kerov多项式$Σ_k$作为一个加权和的格上的非交叉分区的集合$\{1,...,k+1\}$。特别是,这样的公式是有关的偏序$\mirr$上的Lehner的不可约的非交叉分区,可以描述在从左到右的最小值和最大值,下降和超越的排列。这提供了对称群$\frak{S}_k$的凯莱图的公式的翻译,并允许我们通过由Bóna和Simion发现的模式避免置换的偏序集$P_k$和$Q_k$来恢复$Σ_k$的系数。我们还得到了专门的系数$Σ_k$的对称函数。

英文摘要:

We prove a formula expressing the Kerov polynomial $Σ_k$ as a weighted sum over the lattice of noncrossing partitions of the set $\{1,...,k+1\}$. In particular, such a formula is related to a partial order $\mirr$ on the Lehner's irreducible noncrossing partitions which can be described in terms of left-to-right minima and maxima, descents and excedances of permutations. This provides a translation of the formula in terms of the Cayley graph of the symmetric group $\frak{S}_k$ and allows us to recover the coefficients of $Σ_k$ by means of the posets $P_k$ and $Q_k$ of pattern-avoiding permutations discovered by Bóna and Simion. We also obtain symmetric functions specializing in the coefficients of $Σ_k$.

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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