Echo Chamber: RL Post-training Amplifies Behaviors Learned in Pretraining

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Member Seminar Speaker: Samy Jelassi, CMSA Title: Echo Chamber: RL Post-training Amplifies Behaviors Learned in Pretraining Abstract: Reinforcement Learning has become a crucial step in training state-of-the-art language models such as DeepSeek-R1 for solving mathematical problems. In this talk, I will first review the mechanisms of Reinforcement Learning fine-tuning. Then, I will present a systematic end-to-end […]

Resurgence, number theory, and quantum mirror curves 

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Mathematical Physics and Algebraic Geometry Seminar Speaker: Claudia Rella (IHES) Title: Resurgence, number theory, and quantum mirror curves Abstract: Resurgence provides a powerful toolbox to access the non-perturbative sectors hidden within the divergent asymptotic series of quantum theories. Under some special assumptions, the non-perturbative data extracted via resurgent methods possess intrinsic number-theoretic properties that are deeply […]

Factorizations for data analysis

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Colloquium Speaker: Anna Seigal, Harvard University Title: Factorizations for data analysis Abstract: We can find structure in data by factoring it into building blocks, which should be interpretable for the context at hand. A classical example is principal component analysis (PCA), which uses the eigendecomposition of the covariance matrix to find axes of variation in a dataset. Starting from […]

Asset pricing with heterogeneous agents

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Member Seminar Speaker: Sergiy Verstyuk, Harvard CMSA Title: Asset pricing with heterogeneous agents Abstract: This talk will introduce the basics of continuous-time finance, discuss important existing theories and models, as well as present some new asset pricing results in a setting with many heterogeneous investors. (Joint work with Puskar Mondal.)  

Thinking Outside the Ballot Box

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Colloquium Speaker: Ariel Procaccia, Harvard University Title: Thinking Outside the Ballot Box Abstract: How should one design unprecedented democratic processes capable of handling enormous sets of alternatives like all possible policies, bills, or statements? I argue that this challenge can be addressed through a framework called generative social choice, which fuses the rigor of social choice theory […]

Incentives for data sharing in federated learning

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Member Seminar Speaker: Han Shao, Harvard CMSA Title: Incentives for data sharing in federated learning Abstract: Federated learning has recently emerged as a powerful approach for enabling collaboration across large populations of learning agents. However, agents may have incentives to defect from the collaboration—that is, to withdraw or contribute less data than expected—due to the […]

From superspace to twisted supergravity

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Mathematical Physics and Algebraic Geometry Seminar Speaker: Fabian Hahner, University of Washington Title: From superspace to twisted supergravity Abstract: In this talk, I will present a geometric perspective on the pure spinor superfield formalism, which proves fruitful for studying twisted supergravity. For eleven-dimensional supergravity, we use this technique to construct the full interacting theory together with […]

Bass-Note Spectra of locally uniform geometries

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Colloquium Speaker: Peter Sarnak, IAS & Princeton University Title: Bass-Note Spectra of locally uniform geometries Abstract: We formulate and report on the problem of the Bass-Note Spectrum of an invariant operator as one varies over locally uniform geometries. In the Euclidean setting this recasts classical problems of Mahler from the geometry of numbers in a new […]

Mathematical Physics and Algebraic Geometry Seminar

Mass gap in AdS space

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

Mathematical Physics and Algebraic Geometry Seminar Speaker: Ziming Ji, Northeastern University Title: Mass gap in AdS space Abstract: AdS space can be used as an IR regulator of QFT. The asymptotic conformal boundary in AdS space provides rich, unique observables. We study asymptotic free theories in two-dimensional AdS space. By changing the AdS curvature scale \Lambda […]

Machine learning for analytic calculations in theoretical physics

CMSA Room G10 CMSA, 20 Garden Street, Cambridge, MA, United States

New Technologies in Mathematics Seminar Speaker: Matthias Wilhelm (University of Southern Denmark) Title: Machine learning for analytic calculations in theoretical physics Abstract: In this talk, we will present recent progress on applying machine-learning techniques to improve calculations in theoretical physics, in which we desire exact and analytic results. One example are so-called integration-by-parts reductions of […]