应胡泽军教授的邀请，福建师范大学王鹏教授将于7月16-18日前来郑州大学进行学术访问，并就共同感兴趣的微分几何课题开展深入交流与研讨。访问期间，王鹏教授将做学术报告，介绍其与(UMass Amherst)Rob Kusner教授关于Willmore泛函相关课题合作研究的最新成果。报告的具体安排如下：

报告题目：Willmore stability and Morse index of minimal surfaces in spheres

报告人：福建师范大学王鹏教授

报告时间：2019年7月17日（星期三）上午10:00—12:00.
报告地点：数学与统计学院310报告室.

内容提要：Urbano's index theorem on Clifford torus plays an important role in Marques and Neves's proof of Willmore conjecture in S^3. We generalize Urbano's theorem to minimal tori in S^4 by showing that a minimal torus in S^4 has index at least 6 and the equality holds if and only if it is the Clifford torus. It is also natural to ask whether the Clifford torus is Willmore stable when the co-dimension increases and whether there are other Willmore stable tori or not. We answer these problems for minimal tori in S^n, by showing that the Clifford torus in S^3 and the equilateral Bryant-Itoh-Montiel-Ros torus in S^5 are the only Willmore stable minimal tori in arbitrary higher co-dimension. Moreover, the Clifford torus is the only minimal torus (locally) minimizing the Willmore energy in arbitrary higher co-dimension, and the equilateral (Bryant-Itoh-Montiel-Ros) torus is a (local) constrained-Willmore minimizer, but not a (local) Willmore minimizer.