主持人：朱萌

报告人简介：谢君明博士毕业于美国里海大学，师从著名几何学家曹怀东教授，现为美国罗杰斯大学Hill助理教授，已在CVPDE，JGA，Math. Z.等知名期刊上发表若干论文，在扩张Ricci孤立子的曲率估计和四维具有非负迷向曲率的收缩Ricci孤立子的分类方面做出了出色的成果。


报告摘要：Ricci solitons, introduced by R. Hamilton in the mid-80s, are self-similar solutions to the Ricci flow and natural extensions of Einstein manifolds. They often arise as singularity models and hence play a significant role in the study of Ricci flow. In this talk, we will present some recent progress on the geometry and classifications of 4-dimensional gradient Ricci solitons with nonnegative, or half nonnegative, isotropic curvature. This talk is based on a joint work with Huai-Dong Cao.