学术报告

报告人：Reza Naserasr

报告主题：Homomorphisms and colorings of signed graphs

报告时间：2022年12月16日和12月23日19:30-20:30（第1-2场）

报告地点：ZOOM 894 0889 8417，密码：005585

邀请人：白延东

报告摘要：Motivated by the 4-Color theorem, the relation between minor theory and coloring of graphs is one of the most intriguing areas of graph theory. To improve on this relation, the notion minor of signed graphs is introduced and studied since 1970's and some results and conjectures connecting minor of signed graphs and coloring of (unsigned) graphs are presented. In the first part of these lectures we will introduce notions of homomorphisms and colorings of signed graphs. These extensions would provide a better setting to connect the two notions of coloring and minor. After building the required terminology, we will show that homomorphisms to specific family of signed graphs, namely the signed projective cubes, capture special packing problem, which are also strongly related to the 4CT. There will be plenty of open questions for interested students.

报告人简介：Reza Naserasr，法国巴黎西岱大学（Université Paris Cité）教授，法国国家科研中心研究员。2003年获加拿大西蒙菲莎大学博士学位，主要从事图论及其应用方向研究工作，在 J. Combin. Theory Ser. B, J. Graph Theory, SIAM J. Discrete Math., European J. Combin. 等权威期刊发表论文50余篇。