November 14, 2026 at Yale University

GATSBY homepage

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

All are welcome! Please register. 

Schedule 

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

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

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

2 pm  - 3 pm         Lightning talks (Kline Tower 101)

3 pm  - 3:30 pm Break

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

4:30pm         Informal discussion followed by dinner for those interested

Abstracts 

• Matthew Stover

Background Talk: Modular embeddings and Fuchsian groups.

Abstract: Fuchsian groups with modular embeddings have the very special property that their matrix entries are all algebraic numbers, and every unbounded `Galois conjugate' representations $\Gamma^\sigma$  comes equipped with a holomorphic (or conjugate holomorphic) map $\phi^\sigma : \mathbb{H}^2 \to \mathbb{H}^2$ intertwining the actions of $\Gamma$ and $\Gamma^\sigma$ on the upper half-plane $\mathbb{H}^2$. I will first try to convince you that nontrivial examples should not exist. Then we will see that many of the most important classes of Fuchsian groups, triangle groups and lattice Veech groups, provide nontrivial examples. This talk will only require knowledge of Fuchsian groups and some basic complex analysis.

Research Talk: New modular embeddings and applications

Abstract: This talk will start with a construction of Fuchsian groups with a modular embedding coming from complex hyperbolic surfaces. These do not come from any previous construction. I will then discuss some even newer developments giving rigidity and structure theorems for nonarithmetic lattices.

• Lightning talks (in order) 

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 2026, Fall 2025, 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