几何分析讨论班

报告题目：Hyperbolic Monge-Ampere systems with flatness conditions

报告人：胡宇豪（长聘教轨副教授，上海交通大学）

时间：2026年3月31日（星期二）, 下午16:00-17:00

地点：海纳苑2幢101

摘要：For hyperbolic Monge-Ampere systems, Bryant-Griffiths-Grossman's approach to the equivalence problem yields two invariant tensors, S1 and S2, defined on the underlying 5-manifold. These tensors take similar forms, except that one is symmetric and the other anti-symmetric. It is known that `S2=0' is equivalent to the Euler-Lagrange condition, and that `S1=S2=0' characterizes the homogeneous wave equation up to contact transformation. In comparison, little was known for the `S1=0' case. By using Cartan's method of equivalence, our (on-going) analysis for both the S1=0 and S2=0 cases reveals contrasting phenomena, including generality, existence of symmetric examples, and richness of sub-cases defined by flatness conditions on invariants. This talk will be a report on these findings.

报告人简介：胡宇豪，现为上海交通大学数学科学学院（长聘教轨）副教授。本科、博士分别毕业于浙江大学、杜克大学。他近年来从事微分方程几何理论的研究，具体包括外微分系统、Bäcklund变换、双曲Monge-Ampère系统等；也曾参与Riemann几何中和数量曲率相关的研究。

联系人：盛为民（shengweimin@zju.edu.cn）