Cospectral vertices, walk regular graphs and the echolocation problem

发布时间：2026-08-04 作者：浏览次数：

Speaker:	孔诗磊	DateTime:	2026年8月4日（周二）下午16:30-17:30
Brief Introduction to Speaker: 孔诗磊，四川大学		Place:	国交二号楼315会议室
Abstract:We study cospectral vertices on finite graphs in relation to the echolocation problem on Riemannian manifolds. First, we use a computer search to find minimal examples of various types of graphs on which cospectral but non-similar vertices exist, including minimal walk-regular non-vertex-transitive graphs, which turn out to be non-planar. Secondly, as our main result, we classify all finite 3-connected walk-regular planar graphs, proving that such graphs must be vertex-transitive.