Academic Report of School of Mathematical Sciences [2025] No. 125

(Series Report for High-Level University Construction No. 1227)

Title: Ring Lemma for ideal circle patterns

Speaker: Dr. Zhou Puchun (University of Oxford)

Time: 15:00–16:00, November 20, 2025 (Thursday)

Location: Tencent Meeting: 892-921-693

Abstract:

Ring Lemma is an essential lemma controlling the geometric  properties of univalent circle packings.  Inspired by a Ring Lemma proved by Zhengxu He, we introduced a way to generalize the Ring Lemma to the case of ideal circle patterns. In this talk, I will present how the Ring Lemma holds, and is used to prove the existence of infinite ideal circle patterns embedded on the plane. This talk is from the joint work of Huabin Ge and Hao Yu.

Speaker Biography:

Puchun Zhou is currently a postdoctoral researcher at the University of Oxford. He obtained his Ph.D. at Fudan University under the supervision of Bobo Hua. His research focuses on Circle Packing and Discrete Geometry.

All faculty and students are welcome!

Host: Zhou Ze

School of Mathematical Sciences & Mathematics Research Institute

November 19, 2025