In Fall 2026, seminar will run Fridays from 2–3 p.m. in Evans 939. Talks are 50 minutes (starting at 2 Berkeley time = 2:10), and there will be ample time for questions afterwards.
Organized by Aaron Calderon, Srivatsav Kunnawalkam Elayavalli, and Amir Mohammadi.
September 4, 2026
Izhar Oppenheim (Ben-Gurion)
Title: Banach Fixed Point Properties of Universal Lattices
Abstract: Higher-rank universal lattices and Steinberg groups over Z[t_1,…,t_m] can be viewed as generalizations of higher-rank algebraic lattices.
In this lecture, I will discuss results showing that these groups possess the fixed point property for all affine isometric actions on uniformly convex Banach spaces. This result provides a far-reaching extension of my earlier work on Banach property (T) for SL(n,Z) that was later generalized by de Laat and de la Salle for all higher rank algebraic lattices.
September 11, 2026
Claire Burrin (Zurich)
Title: Modular systoles are optimal for the crossing number
Abstract: I will show that the family of systoles on congruence surfaces have minimal crossing number. This is work joint with Sebastian Baader, Luca Studer, and Hugo Parlier.
September 18, 2026
Tina Torkaman (UChicago)
Title: Entropy and self-intersection number of geodesic currents on compact hyperbolic surfaces
Abstract: Let X be a compact hyperbolic surface and C a geodesic current which is a geodesic-flow invariant measure. Denote the measure-theoretic entropy of C by h_X(C). In this talk, assuming C is ergodic, we give an upper bound on h_X(C) in terms of its self-intersection number i(C,C) and the systole of X. In particular, we show that a small self-intersection number forces small entropy.
September 25, 2026
Omri Solan (IAS & Princeton)
Title: TBA
Abstract: TBA
October 2, 2026
Bram Petri (Jussieu)
Title: TBA
Abstract: TBA
October 9, 2026
TBA
October 16, 2026
TBA
October 23, 2026
Liyang Shao (Berkeley)
Title: TBA
Abstract: TBA
October 30, 2026
Wooyeon Kim (KIAS)
Title: TBA
Abstract: TBA
November 6, 2026
Giovanni Forni
Title: TBA
Abstract: TBA
November 13, 2026
Jenya Sapir (Binghamton)
Title: TBA
Abstract: TBA
November 20, 2026
Inga Valentiner-Branth (Ghent)
Title: TBA
Abstract: TBA
November 27, 2026
No seminar: Thanksgiving
December 4, 2026
Megan Roda (IAS)
Title: TBA
Abstract: TBA
December 11, 2026
TBA
Aaron Calderon 