CMSA

New Technologies in Mathematics Seminar
2026-11-04 14:00 - 15:00, 2026-11-18 14:00 - 15:00, 2026-11-25 14:00 - 15:00, 2026-12-02 14:00 - 15:00 (America/New_York) | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
New Technologies in Mathematics Seminar
Speaker: tba

AI for the Working Mathematician
2026-11-04 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
2026-11-05 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

Northeast Conference on Categorical Methods
2026-11-06 09:00 - 2026-11-07 17:00 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Northeast Conference on Categorical Methods
Dates: November 6–​7, 2026
Location: CMSA G10, 20 Garden St., Cambridge MA 02138

This conference is intended to bring together researchers in all areas of mathematics and mathematical physics whose work involves the use of methods from categorical algebra, abstract homotopy theory, and higher category theory. Our goal is to showcase new, exciting research and offer an avenue for researchers from the Northeast US to discuss their work and collaborate with people in this ever-growing community.

There will be time for 4 short talks by early-career mathematicians.

REGISTRATION FORM (link) Deadline: September 20, 2026
Zoom Webinar Registration

Invited Speakers

Andrew Blumberg, Columbia University
Soren Galatius, Columbia University
Tony Pantev, University of Pennsylvania
Nick Rozenblyum, University of Toronto
Tomer Schlank, University of Chicago/Harvard University
Brian Williams, Boston University
Inna Zakharevich, Cornell University

Organized by Dan Freed, Harvard Math & CMSA; Owen Gwilliam, UMass Amherst; and Lorenzo Riva, Harvard CMSA

Member Seminar
2026-11-06 12:00 - 13:00, 2026-11-13 12:00 - 13:00, 2026-11-20 12:00 - 13:00, 2026-12-04 12:00 - 13:00 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States

Colloquium
2026-11-09 16:30 - 17:30, 2026-11-16 16:30 - 17:30, 2026-11-23 16:30 - 17:30, 2026-11-30 16:30 - 17:30, 2026-12-07 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States

Geometry and Quantum Theory Seminar
2026-11-10 16:15 - 18:00, 2026-11-17 16:15 - 18:00, 2026-11-24 16:15 - 18:00, 2026-12-01 16:15 - 18:00 | Science Center 507, 1 Oxford Street, Cambridge, 02138
Joint Math/CMSA Geometry and Quantum Theory Seminar

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

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

AI for the Working Mathematician
2026-12-02 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
AI for the Working Mathematician
Speaker: Mark Selke, Harvard
Title: TBA

Geometry and Mathematical Physics seminar
2026-12-03 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Geometry and Mathematical Physics seminar
Speaker: Paul Feehan, Rutgers University
Title: TBA

Differential Geometry and Physics Seminar
2026-12-03 16:30 - 17:30 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States

Mathematical Economics Seminar:
2026-12-08 14:00 - 16:00 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States

Stable Homotopy Theory and Arithmetic Geometry
2027-02-15 08:00 - 2027-05-15 17:00 | CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Stable Homotopy Theory and Arithmetic Geometry
Dates: Feb 15–May 15, 2027
Location: Harvard CMSA, 20 Garden St, Cambridge MA
This program will focus on interactions between stable homotopy theory and arithmetic geometry. In recent years, ideas from homotopy theory have begun to play an important role in areas such as p-adic cohomology, prismatic methods, and aspects of the Langlands program, while techniques from arithmetic geometry have led to new insights and computations in chromatic homotopy theory. Despite this growing overlap, researchers in the two areas often use different languages and tools. A central goal of the program is to make these ideas more accessible across fields and to encourage collaborations around shared problems.
The program will run from February 15 to May 15 and will be built around research and informal collaboration. It will begin with a short introductory bootcamp, followed by two focused workshops (one near the start and one toward the end), a weekly seminar with broadly accessible talks, and a weekly open-problem session. Most of the time will be left open for discussion and joint work among participants, aiming to spark new projects and longer-term connections between the two communities.
The program will include:
(1) a bootcamp during the week Feb. 22–26, consisting of introductory lectures on both subjects;
(2) two research workshops—one during Mar. 1–5 and one during May 3–7—highlighting current developments, especially those at the interface of the two areas;
(3) a weekly seminar featuring talks of broad relevance to participants; and
(4) a weekly open-problem seminar aimed at proposing and developing collaborative research directions, both for the duration of the program and beyond.
Register Online

Organizers: Tomer Schlank (Harvard), Jared Weinstein (Boston University), Mark Kisin (Harvard), Jeremy Hahn (MIT), Lucas Mann (Münster)

Stable Homotopy Theory and Arithmetic Geometry Boot Camp
2027-02-22 09:00 - 2027-02-26 17:00 | CMSA Room G10, CMSA, 20 Garden Street, Cambridge, MA, 02138, United States
Stable Homotopy Theory and Arithmetic Geometry Boot Camp
Dates: February 22-26, 2027
