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Pagina d'informazione di seminari ed eventi scientifici che avranno luogo settimanalmente per lo più in area romana. Per la pubblicazione rivolgersi a Giorgio Chiarati che ne cura la gestione. Per consultare la pagina di tutti i seminari di Dipartimento Click here.

 

Settimana 19/02/2024 - 23/02/2024

 


 

Seminari

 

Università degli Studi Roma Tor Vergata
Dipartimento di Matematica

 


Rome Centre on Mathematics for Modelling and Data ScienceS (RoMaDS) Mini-course seminar

Date: 19-22th February 2024
Schedule:
Mon 14h00-17h00
Wed 09h30-12h30
Thu 09:30-12:30
Where: Conference Room 1201 "R. Dal Passo"
Title: " An introduction to Score-based Generative Models "
Speaker:
Alain Durmus - École Polytechnique, Paris
Giovanni Conforti - École Polytechnique, Paris

Abstract: In simple words, generative modeling consists in learning a map capable of generating new data instances that resemble a given set of observations, starting from a simple prior distribution, most often a standard Gaussian distribution. This course aims at providing a mathematical introduction to generative models and in particular to Score-based Generative Models (SGM). SGMs have gained prominence for their ability to generate realistic data across diverse domains, making them a popular tool for researchers and practitioners in machine learning. Participants will learn about the methodological and theoretical foundations, as well as some practical applications associated with these models. The first two lectures motivate the use of generative models, introduce their formalism and present two simple though relevant examples: energy-based models and Generative Adversarial Networks. In the third and fourth lecture we present score-based diffusion models and explain how they provide an algorithmical framework to the basic idea that sampling from the time-reversal of a diffusion process converts noise into new data instances. We shall do so following two different approaches: a first elementary one that only relies on discrete transition probabilities, and a second one based on stochastic calculus. After this introduction, we derive sharp theoretical guarantees of convergence for score-based diffusion models assembling together ideas coming from stochastic control, functional inequalities and regularity theory for Hamilton- Jacobi-Bellman equations. The course ends with an overview of some of the most recent and sophisticated algorithms such as flow matching and diffusion Sch¨odinger bridges (DSB), which bring an (entropic) optimal transport insight into generative modeling. .

This talk is part of the activity of the MIUR Excellence Department Projects MatMod@TOV.

Organizing Committee:
Domenico Marinucci - Coordinator - (mail to contact)
Michele Salvi (mail to contact)
Stefano Vigogna (mail to contact)
Further Info: Click here for RoMaDS events Page
Streaming Link (MS Teams): This seminar will be held in mix mode: in person and video streaming: -> MS TEAMS LINK for streaming


Università degli Studi Roma Tor Vergata
Dipartimento di Matematica

 


Geometry Seminar

Date: 20th February 2024
Schedule: 14:30 - Rome Time
Where: Conference Room 1101 "C. D'Antoni"
Title: " CM-minimizers and standard models of Fano fibrations over curves "
Speaker: Maksym Fedorchuk - Boston College

Abstract: A recent achievement in K-stability of Fano varieties is an algebro-geometric construction of a projective moduli space of K-polystable Fanos. The ample line bundle on this moduli space is the CM line bundle of Tian. One of the consequences of the general theory is that given a family of K-stable Fanos over a punctured curve, the polystable filling is the one that minimizes the degree of the CM line bundle after every finite base change. A natural question is to ask what are the CM-minimizers without base change. In answering this question, we arrive at a theory of Kollár stability for fibrations over one-dimensional bases, and standard models of Fano fibrations. After explaining the general theory, I will sketch work in progress on standard models of quartic threefold hypersurfaces. This talk is based on joint work with Hamid Abban and Igor Krylov.

This talk is part of the activity of the MIUR Excellence Department Projects MatMod@TOV, and the PRIN 2022 Moduli Spaces and Birational Geometry

Organizing Committee:
Giulio Codogni (mail to contact)
Guido Maria Lido (mail to contact)
Further Info: Click here for Geometry events Page
Streaming Link (MS Teams): This seminar will be held in person



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