报告人: 韩 斌（法国里昂第一大学）

日  期: 2019年11月11日

时  间: 上午10:30

地  点: 理科楼 LD202

摘  要: A formula of Stembridge states that the permutation peak polynomials and descent  polynomials are connected  via a quadratique transformation. Rephrasing  the latter  formula  with permutation cycle peaks and excedances  we are able to prove a series of general formulas expressing polynomials counting permutations by various excedance statistics in terms of refined Eulerian polynomials. Our methods include permutation enumeration techniques  involving variations of classical bijections from permutations to Laguerre histories, explicit continued fraction expansions of combinatorial generating functions. This talk is based on joint work with Jianxi MAO and Jiang ZENG.

报告人简介：韩斌，博士毕业于法国里昂第一大学和兰州大学，研究方向为计数组合学里面的排列统计量、连分式、组合序列的伽马正性等，已在应用数学进展（Adv. Appl. Math.）和电子组合（Electron. J. Combin.）等期刊发表论文。

学院联系人:傅士硕

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