CAMGSD
IST FCT EditPT | EN

Seminars and short courses RSS feed

Seminars, for informal dissemination of research results, exploratory work by research teams, outreach activities, etc., constitute the simplest form of meetings at a Mathematics research centre.

CAMGSD has recorded the calendar of its seminars for a long time, this page serving both as a means of public announcement of forthcoming activities but also as a historic record.

For a full search interface see the Mathematics Department seminar page.

Europe/Lisbon —

Topological Quantum Field Theory

Cris Negron, University of Southern California.

I will discuss joint work with Agustina Czenky. We introduce a $(3-ε)$-dimensional TQFTs which is generated, in some sense, by the derived category of quantum group representations. This TQFT is valued in the $∞$-category of dg vector spaces, and the value on a genus $g$ surface is a $g$-th iterate of the Hochschild cohomology for the aforementioned category. I will explain how this TQFT arises as a derived variant of the usual Reshetikhin–Turaev theory and, if time allows, I will discuss the possibility of introducing local systems into the theory. Our interest in local systems comes from proposed relationships with 4-dimensional non-topological QFT.

Europe/Lisbon —

Room P3.10, Mathematics Building Instituto Superior Técnico https://tecnico.ulisboa.pt

Mathematics for Artificial Intelligence

Mário Figueiredo, IT & Instituto Superior Técnico.

This lecture first provides an introduction to classical variational inference (VI), a key technique for approximating complex posterior distributions in Bayesian methods, typically by minimizing the Kullback-Leibler (KL) divergence. We'll discuss its principles and common uses.

Building on this, the lecture introduces Fenchel-Young variational inference (FYVI), a novel generalization that enhances flexibility. FYVI replaces the KL divergence with broader Fenchel-Young (FY) regularizers, with a special focus on those derived from Tsallis entropies. This approach enables learning posterior distributions with significantly smaller, or sparser, support than the prior, offering advantages in model interpretability and performance.

Reference: S. Sklavidis, S. Agrawal, A. Farinhas, A. Martins and M. Figueiredo, Fenchel-Young Variational Learning,
https://arxiv.org/pdf/2502.10295

Europe/Lisbon —

Room P3.10, Mathematics Building Instituto Superior Técnico https://tecnico.ulisboa.pt

Mathematics for Artificial Intelligence

Mário Figueiredo, IT & Instituto Superior Técnico.

This lecture first provides an introduction to classical variational inference (VI), a key technique for approximating complex posterior distributions in Bayesian methods, typically by minimizing the Kullback-Leibler (KL) divergence. We'll discuss its principles and common uses.

Building on this, the lecture introduces Fenchel-Young variational inference (FYVI), a novel generalization that enhances flexibility.FYVI replaces the KL divergence with broader Fenchel-Young (FY) regularizers, with a special focus on those derived from Tsallisentropies. This approach enables learning posterior distributions with significantly smaller, or sparser, support than the prior, offering advantages in model interpretability and performance.

S. Sklavidis, S. Agrawal, A. Farinhas, A. Martins and M. Figueiredo, Fenchel-Young Variational Learning,
https://arxiv.org/pdf/2502.10295

Europe/Lisbon —

Topological Quantum Field Theory

Joshua Sussan, Medgar Evers College, The City University of New York.

We construct an action of sl(2) on equivariant Khovanov–Rozansky link homology. We will discuss some topological applications and show how the construction simplifies in characteristic p. This is joint with You Qi, Louis-Hadrien Robert, and Emmanuel Wagner.

Current funding: FCT UIDB/04459/2020 & FCT UIDP/04459/2020.

©2025, Instituto Superior Técnico. All rights reserved.