Geometric Topology Fair 2019

KAIST Advanced Institute for Science-X (KAIX) hosts a thematic program this summer. As a part of the program, 17th Geometric Topology Fair will run from July 28th to August 3rd at the department of Mathematical Sciences, KAIST.  

Every one is welcome, Here is a direction for how to come to Daejeon and KAIST. 
If you want to participate, please register by sending a short email to 
kaixmathschool(at) with the heading [GT19] in the title. 

All talks are at the building E6-1, Room 1401. 
The schedule is as in the table below. 

   July 29 July 30  July 31   Aug 1  Aug 2 
Free discussion
Bestvina FujiwaraLee Free discussion
14:30-15:30 Registration Baba FuLiu Free discussion
15:30-16:00 Registration coffee/
Free discussion coffee/

16:00-17:00 Registration Masai Free discussion Wu

Shinpei Baba (Osaka University) 

Mladen Bestvina (University of Utah) 
Title: Proper actions on finite products of quasi-trees. 
Abstract: We say that a finitely generated group G has property (QT) if it acts isometrically on a finite product of quasi-trees so that orbit maps are quasi-isometric embeddings. This property is a strong form of finiteness of asymptotic dimension. We prove that residually finite hyperbolic groups and mapping class groups have property (QT). The latter statement was also announced by Ursula Hamenstadt, but her approach is different. This is joint work with Ken Bromberg and Koji Fujiwara.

Ser-Wei Fu (NCTS, National Taiwan University)
Title: Slices of quadratic differentials and finite length rigidity 
Abstract: Quadratic differentials are natural objects used to describe Teichmuller geodesics. Flat surfaces induced by quadratic differentials are of interest on their own as they are related to billiards and CAT(0) geometry. It is known that for a fixed topological surface, a hyperbolic metric is uniquely determined (up to isotopy) by the length of a finite set of simple closed curves but a flat metric doesn’t share the same property. It is therefore of interest to restrict to subsets of flat metrics when considering the finite length rigidity property. In this talk I will consider slices of quadratic differentials that share a vertical measured foliation and discuss some preliminary observations.

Koji Fujiwara (Kyoto University)

Yi Liu (Peking University) 

Hidetoshi Masai (Tokyo Tech)

Chenxi Wu (Rutgers University)