Generalizations of the Four Color Theorem
发布人: 曹思圆   发布时间: 2018-07-05   浏览次数: 25

主讲人:郁星星教授  (美国 Georgia Institute of Technology)

主持人:詹兴致 教授



主办单位:数学科学学院 科技处

报告人简介:郁星星教授是杰出的图论学家,在图的结构和图论算法两方面都做出了重要贡献,解决了很多难题,包括证明了著名的有40年历史的 Kelmans-Seymour猜想。郁教授的丰硕成就受到了同行的广泛尊敬。郁教授是如下著名学术杂志的编委:Discrete Mathematics,中国科学,SIAM J. Discrete Mathematics, J. of Combinatorics.

报告内容简介:The Four Color Theorem  states that planar graphs are 4-colorable, i.e. there is an assignment of 4 colors to the vertices of a planar graph (one color for each vertex) such that adjacent vertices receive different colors. There are several possible ways to generalize this result. For example, one may consider graphs embeddable in a surface with fixed genus, or one can consider integer flows in graphs. In this talk, I will discuss two well known conjectures about graph coloring: Hadwiger's conjecture and Hajos' conjecture on graphs not containing the K_k as a minor or as a topological minor.