时间：2024.8.3（周六）上午9:00-10:30

地点：数学楼2-3会议室

题目：Homomorphism, cover and quotient for signed multidigraphs

摘要：Does there exist a homomorphism between two graphs (signed graphs or signed mutidigraphs) such that it inherits some graph properties ? Specifically, it inherits the properties for the eigenvalues, and has some contributions to construct cospectral graphs and characterize some class of graphs ?

In this talk, we introduce the concept of LAC-homomorphism in signed mutidigraphs. Under LAC-homomorphism we have established homomorphic classification for signed mutidigraphs, where each class has some genetic properties of graph structure and eigenvalues, which makes it possible for us to construct the cospectral graphs and to characterize some special graph classes. In addition, our results are generalizations for the related results of graph homomorphism, graph cover and quotient.

报告人简介：黄琼湘，新疆大学教授、博士生导师，主要研究领域为图论、代数图论、图谱理论。在J. Combin. Theory Ser. B、Europ. J. Combin.、J. Algebraic Combin.、Electronic. J. Combin.、Discrete Math.、Discrete Appl. Math.、Linear Algebra Appl. 等图与组合领域的期刊上发表论文150余篇；主持完成国家自然科学基金项目多项，作为子课题负责人承担国家自然科学基金重点项目1项；荣获新疆维吾尔自治区科技进步奖等。