报告题目：The signed graphs with symmetric spectra
报告人：黄琼湘
摘要：It is well known that a graph $G$ has a symmetric spectrum if and only if it is bipartite, a signed graph $\Gamma=(G,\sigma)$ has a symmetric spectrum if $G$ is bipartite. However, there exists a spectrally symmetric signed graph $\Gamma=(G,\sigma)$ such that $G$ is not bipartite. In this paper, we focus to characterize the signed graphs with symmetric spectra. Some necessary and (or) sufficient conditions for spectrally symmetric signed graphs are given. Moreover, some methods to construct signed graphs with symmetric spectra are found and infinite families of these signed graphs are produced. Particularly, spectrally symmetric signed graphs of some classes are completely determined.
报告时间：2023年3月29日 15:30
报告地点：一教116
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。