报告题目：Cores of graphs: an introductory overview

报 告 人：周三明教授(墨尔本大学）

报告时间：2026年4月9日（星期四）10:00-11:00

Zoom：88018952468，(Link:https://unimelb.zoom.us/j/88018952468?pwd=YXM4UXlFcXo4clRQdmJubFNMZlJVQT09)

Password：072730

主持人：乔守红

报告摘要：A retract of a graph X is an induced subgraph Y of X such that there exists a homomorphism from X to Y whose restriction to Y is the identity map. A graph is a core if it has no nontrivial retracts. In general, the minimal retracts of a graph are cores and are unique up to isomorphism; they are called the core of the graph. This talk will be an introductory overview of the study of cores of graphs, with an emphasis on a few classes of vertex-transitive graphs, strongly regular graphs and arc-transitive graphs. 

专家简介：Sanming Zhou is a professor in the School of Mathematics and Statistics, The University of Melbourne, Australia, where he has been working ever since the completion of his PhD at The University of Western Australia in 2000. He has broad research interests ranging from algebraic graph theory, graph theory, combinatorial optimization, to combinatorial problems from theoretical computer science. In 2003 he was awarded a Kirkman Medal of the Institute of Combinatorics and Its Applications, and from 2012 to 2015 he held a prestigious Future Fellowship supported by Australian Research Council.Sanming Zhou was co-editor-in-chief of the Australasian J. Combinatorics from 2018 to 2022. At present, he serves as editor-in-chief of Congressus Numerantium. He is an editor of J. Algebraic Combinatorics (Springer), Graphs and Combinatorics (Springer), Bulletin of the Malaysian Mathematical Sciences Society (Springer), and J. Interconnection Networks (World Scientific). He served as president of the Combinatorial Mathematics Society of Australasia in 2017 and vice president of this organization from 2014 to 2016.