ON THE COMPLEXITY OF EXTENSIONS
OF CLI POLISH GROUPS
报告专家：丁龙云 教授（南开大学）
报告时间：7月22日（周二） 下午14:30--15:30
报告地点：数学学院西202
报告摘要：
We say a Polish group is CLI if it admits a compatible complete left-invariant metric. Let G be a Polish group and H a closed normal subgroup of G. It is well known that G is CLI iff both H and G/H are CLI. In recent years, for characterizing the complexity of CLI Polish groups, some ranks and hierarchies on CLI Polish groups are defined by several researchers. Then a question naturally arises: Can the upper bound of rank of G be determined from the ranks of H and G/H? In this talk, we present some new results concerning this question. This is a joint work with Xu Wang.
邀请人：寇辉&何家亮
