报告人：何翔（清华大学）

时间：2026年7月1日，15:30-16:30

地点：二教2206

题目:  Short geodesics and multiplicities of eigenvalues of hyperbolic surfaces

摘要：In this talk, we give two new upper bounds on the multiplicity of Laplacian eigenvalues for closed hyperbolic surfaces in terms of the number of short closed geodesics and the genus g. For example, we show that if the number of short closed geodesics is sublinear in g, then the multiplicity of the first eigenvalue is also sublinear in g. This makes new progress on a conjecture by Colin de Verdière in the mid 1980s. This is a joint work with Yunhui Wu and Haohao Zhang.