应兰州大学数学与统计学院邀请，中国矿业大学颜棋博士2023年5月4日作线上学术报告。

报告题目：Partial-dual genus polynomials and signed intersection graphs

时间：2023年5月4日（周四）16:30-17:30

地点：腾讯会议（会议ID: 339-903-792）

摘要：Recently, Gross, Mansour and Tucker introduced the partial- dual polynomial of a ribbon graph as a generating function that enumerates the partial duals of the ribbon graph by Euler genus. It is analogous to the extensively-studied polynomial in topological graph theory that enumerates by Euler genus all embeddings of a given graph. To investigate the partial-dual polynomial one only needs to focus on bouquets. In this talk, we shall further show that the partial-dual polynomial of a bouquet essentially depends on the signed intersection graph of the bouquet rather than on the bouquet itself. We then give a characterization of when a bouquet has a planar partial dual in terms of its signed intersection graph. Finally we consider a conjecture posed by Gross, Mansour and Tucker that there is no orientable ribbon graph whose partial-dual polynomial has only one non-constant term, this conjecture is false and we give a characterization of when all partial duals of a bouquet have the same Euler genus. (Joint work with Xian’an Jin)

报告人简介

颜棋，厦门大学博士毕业，中国矿业大学讲师，硕士生导师。研究方向：拓扑图论，主持国家自然科学基金（青年）项目一项，在《Forum Math. Sigma》、《Adv. in Appl. Math.》、《J. Combin. Theory Ser. A》、《European J. Combin.》等国内外数学期刊上发表学术论文26余篇。

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