报告人: Seog-Jin Kim教授

工作单位: 韩国建国大学

报告时间:5月29日下午4:00

报告地点：学院一楼报告厅

报告摘要：

An r-dynamic k-coloring of a graph G is a proper k-coloring _ such that for any vertex v, v has at least minfr; degG(v)g distinct colors in NG(v). The r-dynamic chromatic number _dr(G) of a graph G is the least k such that there exists an r-dynamic k-coloring of G. The list r-dynamic chromatic number of a graph G is denoted by chdr(G). Loeb, Mahoney, Reiniger and Wise (2018) showed that if G is a planar graph, then _d3 (G) _ 10, and there is a planar graph G with_d3 (G) = 7. Thus _nding an optimal upper bound on _d3 (G) for a planar graph G is a natural interesting problem. In this paper, we show that _dr(G) _ 5 if G is a planar triangulation. The upper bound is sharp. This is joint work with Yoshihiro Asayama, Yuki Kawasaki, Atsuhiro Nakamoto, and Kenta Ozeki.

报告人简介：

Seog-jin Kim，韩国建国大学教授，2003年获得美国伊利诺伊大学香槟分校博士学位，主要研究图分解和图染色问题，在《J.Combin.TheorySer. B》，《J.Graph Theory》,《Discrete Math.》等国际著名SCI期刊发表30多篇学术论文。

#from：http://maths.henu.edu.cn/info/1021/2651.htm