时间：2019年7月5日（星期五）  10:00-11:00

地点：数理学院教2楼108室

讲座题目：The generalized Yamada polynomial of virtual spatial graphs

主讲人：金贤安教授

讲座摘要：Knot theory can be generalized to virtual knot theory and spatial graph theory. In 2007, Fleming and Mellor combined and generalized them to virtual spatial graph theory in a combinatorial way.

In this talk, we shall generalize the classical Yamada polynomial for spatial graphs to obtain the generalized Yamada polynomial for virtual spatial graphs via their diagrams. Then we prove that it can be normalized to be a rigid vertex isotopic invariant of virtual spatial graphs and to be a pliable vertex isotopic invariant for virtual spatial graphs with maximum degree at most 3.

We also consider the connection and difference between the generalized Yamada polynomial and the Dubrovnik polynomial of a classical link. That is, the generalized Yamada polynomial specializes to a version of the Dubrovnik polynomial for classical links such that it can be used to sometimes detect the non-classicality of virtual links.This is joint work with Qingying Deng and Louis H. Kauffman.

专家简介：金贤安，厦门大学数学科学学院教授，博士生导师，副院长。主要从事图论、组合纽结论及其应用的研究工作。迄今为止，已在Adv. Appl. Math., J. Graph Theory, Proc. Amer. Math. Soc. ,Topol. Appl.等杂志发表学术论文50余篇。先后主持国家自然科学基金项目3项，参加国家自然科学基金重点项目1项。曾在第6届组合数学与图论大会、中国数学会2013年和2018年学术年会、第7届亚洲数学大会、The 33rd Summer Conference on Topology and its Applications等国际和国内学术会议作邀请报告。

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数理学院