应学院邀请,湖南师范大学黄元秋教授将在线作学术报告。
报告题目:On the sizes of matchings in 1-planar graphs with high minimum degree
报告摘要:A matching of a graph is a set of edges without common end vertex. A graph is called 1-planar if it admits a drawing in the plane such that each edge is crossed at most once. Recently, Biedl and Wittnebel proved that every 1-planar graph with minimum degree 3 and n≥7 vertices has a matching of size at least (n+12)/7, and this is tight for some graphs; they also provided tight lower bounds on the matching of sizes for 1-planar graphs with minimum degree 4 and 5. In this paper, we show that any 1-planar graph with minimum degree 6 and n≥32 vertices has a matching of size at least (3n+4)/7, and this lower bound is tight. Our result confirms a conjecture posed by Biedl and Wittnebel.
报告时间:2022年10月24日9:30
邀 请 人:姚海元 副教授
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报告人简介
黄元秋, 湖南师范大学二级教授、博士、博士生导师,教育部“新世纪优秀人才”入选者,湖南省普通高校学科带头人。现为湖南师范大学皇冠正规娱乐平台副院长、中国组合数学与图论学会理事、中国运筹学会理事、湖南省数学学会常务理事。1996年博士毕业于中国科学院应用数学研究所, 主要从事图论与组合中相关问题的研究,包括图的亏格及最大亏格、图在曲面上的嵌入分布、图的交叉数、图的k-平面性等。在 J. Combin. Theory Ser. B、J. of Graph Theory、Discrete Mathematics、Discrete Applied Mathematics、Euro. Combin.、The Electronic Journal of Combinatorics、Graphs and Combinatorics以及 《中国科学》等国内外学术期刊上发表论文120余篇。主持完成国家自然科学基金项目5项,在研国家自然科学基金1项,主持完成省部级科研项目多项。