應yl7703永利官網(wǎng)張和平教授和高毓平副教授邀請，美國奧本大學鐔松齡助理教授將于2023年12月12日-12月24日訪問蘭州大學，期間于12月14日舉辦學術(shù)報告。

報告題目：Graph Edge Coloring and the Overfull Conjecture

報告時間：2023年12月14日下午4:00

報告地點：城關(guān)校區(qū)理工樓631

報告摘要：Let $G$ be a simple graph. An edge coloring of $G$ is an assignment of colors to the edges of $G$ so that any two adjacent edges receive distinct colors. The smallest number of colors needed in such an assignment is the chromatic index of $G$. Clearly, we need at least $\Delta(G)$, the maximum degree of $G$, this many colors. On the other hand, Vizing in 1965 proved that at most $\Delta(G)+1$ colors are sufficient. According to their chromatic index, we naturally classify all simple graphs into class 1 (those with chromatic index equal to their maximum degree) or class 2, but the classification problem is NP-complete. However, when a graph has ``too many’’edges, the graph is trivially class 2. Conversely, Chetwynd and Hilton in 1985 made the Overfull Conjecture: if a graph $G$ satisfies $\Delta(G)>|V(G)|/3$, then $G$ is class 2 also implies that $G$ or some subgraph of $G$ has too many edges. In this talk, we look at some recent progress toward the conjecture.

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報告人簡介

鐔松齡，美國奧本大學助理教授，主要研究方向為結(jié)構(gòu)圖論、圖染色與極值圖論。于2015年從美國佐治亞州立大學獲得博士學位，2015-2018年在美國范德堡大學從事博士后研究工作。截止目前，在J. Combinatorial Theory Ser. B，J. Graph Theory等圖論與組合方向的頂級期刊發(fā)表高水平學術(shù)論文四十幾篇，解決了圖論領(lǐng)域的幾個公開問題和猜想。

甘肅省高校應用數(shù)學與復雜系統(tǒng)省級重點實驗室

yl7703永利官網(wǎng)

萃英學院

2023年12月11日