November 8, 2025 at Yale University

GATSBY is a conference organized by the geometry/topology groups at Brown and Yale. 

All are welcome! Please register. 

Schedule 

10:45-11:15 Reception (8th floor Kline Tower)

11:15-12:15  Background talk (Kline Tower 101)

12:15-2 Lunch (catered, 8th floor Kline Tower)

2-3 Lightning talks (Kline Tower 101)

3-3:30 Break

3:30-4:30 Research talk (Kline Tower 101)

4:30 Informal discussion followed by dinner for those interested

Abstracts 

• Joseph Maher

Background Talk: Geodesics in geometric spaces

As background and motivation for the subsequent talk, we review the some

classical results about geodesics and random walks in hyperbolic surfaces,

and other spaces with well behaved geometric properties.

Research Talk: Singularity of measures for Cannon-Thurston maps.

Abstract:  Cannon and Thurston showed that a hyperbolic 3-manifold that

fibers over the circle gives rise to a sphere filling curve. The universal

cover of the fiber surface is quasi-isometric to the hyperbolic plane,

whose boundary is a circle, and the universal cover of the 3-manifold is

3-dimension hyperbolic space, whose boundary is the 2-sphere. Cannon and

Thurston showed that the inclusion map between the universal covers

extends to a continuous map between their boundaries, whose image is

dense. In particular, any measure on the circle pushes forward to a

measure on the 2-sphere using this map. We consider Lebesgue measure on

the circle, and the hitting measures associated to random walks on the

surface group, and compare their push forwards onto the 2-sphere with

Lebesgue measure on the 2-sphere and with the hitting measures from random

walks on the 3-manifold group.  We show that typical geodesics have

different behaviours for surface measures as opposed to 3-manifold

measures, and this shows that the surface measures are mutually singular

with respect to the 3-manifold measures.

This is joint work with Vaibhav Gadre, Catherine Pfaff and Caglar Uyanik.

• Lightning talks (in order) 

Thomas Ng (Brandeis): Random quotients preserve negative curvature

Junzhi Huang (Yale): Geometry of transverse surfaces to pseudo-Anosov flows

Joaquin Lema (BC): SL(3,R) Hitchin representations from the inside

Michael Horzepa (Wesleyan): Sectional curvature in semisimple Lie groups

Qingfeng Lyu (BC): Persistently foliar (1,1) non-L-space knots

Dongryul Kim (Yale): Invariant Radon measures on ML for subgroups of mapping class group

Matthew Zevenbergen (BC): Separating nested Margulis tubes

Local information

Locations below have free parking during the weekend.

Organizers:  Tam Cheetham-West, Ethan Dlugie, Yair Minsky, Bena Tshishiku, Tianqi Wang

Previous iterations: Spring 2025, Fall 2024, Spring 2024, Fall 2023, Spring 2023, Fall 2022, Spring 2019, Fall 2015, Spring  2015, Fall 2014, Spring 2014, Fall 2013,  Spring 2013, Spring 2012