CMSA

Geometry and Mathematical Physics Seminar
2026-10-15 16:30 - 17:30 (America/New_York) | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Geometry and Mathematical Physics Seminar
Speaker: Spiro Karigiannis, University of Waterloo

Member Seminar
2026-10-16 12:00 - 13:00, 2026-10-23 12:00 - 13:00, 2026-10-30 12:00 - 13:00, 2026-11-06 12:00 - 13:00, 2026-11-13 12:00 - 13:00 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States

Colloquium
2026-10-19 16:30 - 17:30, 2026-10-26 16:30 - 17:30, 2026-11-09 16:30 - 17:30, 2026-11-16 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States

Geometry and Quantum Theory Seminar
2026-10-20 16:15 - 18:00, 2026-10-27 16:15 - 18:00, 2026-11-03 16:15 - 18:00, 2026-11-10 16:15 - 18:00, 2026-11-17 16:15 - 18:00 | Science Center 507, 1 Oxford Street, Cambridge, 02138
Joint Math/CMSA Geometry and Quantum Theory Seminar

New Technologies in Mathematics Seminar
2026-10-21 14:00 - 15:00, 2026-10-28 14:00 - 15:00, 2026-11-04 14:00 - 15:00, 2026-11-18 14:00 - 15:00 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
New Technologies in Mathematics Seminar
Speaker: tba

AI for the Working Mathematician
2026-10-21 16:30 - 17:30, 2026-10-28 16:30 - 17:30, 2026-11-04 16:30 - 17:30, 2026-11-18 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
AI for the Working Mathematician
Speaker: TBA
Title: TBA

Geometry and Mathematical Physics Seminar
2026-10-22 16:30 - 17:30, 2026-10-29 16:30 - 17:30, 2026-11-12 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States

Colloquium
2026-11-02 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Colloquium
Speaker: Ivan Corwin (Columbia University)

Geometry and Mathematical Physics Seminar
2026-11-05 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Geometry and Mathematical Physics Seminar
Speaker: Ron Donagi, University of Pennsylvania

Mathematical Economics Seminar: Experimental Design in Networks
2026-11-17 14:00 - 16:00 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Speaker: Christopher Harshaw (c.harshaw@columbia.edu), Columbia University
Title: Design-Based Minimax Theory for Network Experiments
Abstract: Network experiments are used throughout the social and medical sciences to investigate causal effects under the presence of interference. While a large body of work has developed improved statistical procedures, the fundamental limits of statistical estimation in these settings is less well understood. In this paper, we develop and investigate a design-based theory of minimax risk for network experiments under an arbitrary neighborhood interference model. Our notion of minimax risk describes the optimal precision among all statistical procedures for investigating a particular causal effect on the observed interference network. We show that the minimax risk is a function of the corresponding conflict graph, which captures inherent unobservability of estimand-relevant potential outcomes given the observed interference network. Our main contribution is a series of upper and lower bounds on the minimax rate in terms of local and global connectivity properties of the conflict graph. To illustrate their utility, we apply these general results to obtain minimax analyses for two commonly studied effects: the direct treatment effect and global average treatment effect.

Speaker: Evan Munro (evan.munro@chicagobooth.edu), University of Chicago, Booth School of Business
Title: Robust Signal Maximization in Spillover Experiments
Abstract: We study the optimal design and analysis of experiments for estimating spillover effects. Assuming a known (e.g., linear) exposure mapping, we characterize the treatment-assignment distribution and regression-based estimator that minimize worst-case asymptotic variance against a broad class of distributions of unobservables. The design problem yields an intuitive solution in which the planner trades off spillover signal strength against diffusion of spillover variation. The analysis problem yields a simple recentered instrumental variable estimator to best leverage this variation. This framework produces natural solutions in several benchmark cases – such as clustered exposure – and suggests computationally tractable approximations for general networks, including bipartite settings. We illustrate these new tools in semi-synthetic experiments based on two applications from development economics. Our approach yields large standard error reductions in both experiments, increasing effective sample sizes by 50-100% or more.

Geometry and Mathematical Physics seminar
2026-11-19 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Geometry and Mathematical Physics seminar
Speaker: Joshua Greene, Boston College
