Thu, April 16, 2026
8:00 pm - 9:00 pm
Online, via Zoom
Yunhui Wu
Tsinghua University
Title
Visibility Spaces and Group Actions
Abstract
We investigate the algebraic structures of groups that act properly discontinuously by isometries on proper, nonpositively curved visibility CAT(0) spaces. We first consider the case where the space is a visibility manifold with bounded curvature and the group consists of parabolic isometries fixing a common point at infinity. We then turn to the case of general CAT(0) visibility spaces with bounded geometry and show that the so-called “Meta conjecture” holds in this setting. This is based on two joint projects with Ran Ji.
Zoom Link: https://osu.zoom.us/j/95047692331?pwd=ojnukWXqCe5jn5vy7AzDn4FpJuwPo5.1