Noticias en español
Seminars appear in decreasing order in relation to date. To find an activity of your interest just go down on the list. Normally seminars are given in English. If not, they will be marked as Spanish Only.
Integrability, gravitation and field theories.
Abstract: The fruitful relationship between physics and integrability has been widely tested by different approaches. They appear, for example, in areas like gravitation and condensed matter physics using holographic or generating solution techniques. In this talk I will review some recent developments connecting integrable models, gravitation, non-Hermitian physics and field theories. The relationship between the AKNS hierarchy and anti-de Sitter three dimensional gravity will be discussed as well as the stability of complex solitons having...
A PTAS for Unsplittable Flow on a Path.
Abstract: In the Unsplittable Flow on a Path problem (UFP) we are given a path with edge capacities, and a set of tasks where each task is characterized by a subpath, a demand, and a weight. The goal is to select a subset of tasks of maximum total weight such that the total demand of the selected tasks using each edge e is at most the capacity of e. The problem admits a QPTAS [Bansal, Chakrabarti, Epstein, Schieber, STOC’06; Batra, Garg, Kumar, Mömke, Wiese, SODA’15]. After a long sequence of improvements [Bansal, Friggstad,...
Statistical Matching using KCCA, Super-OM and Autoencoders-CCA
Cédric HEUCHENNE, Université de Liège, Belgium Abstract: The potential to study and improve different aspects of our lives is ever growing thanks to the abundance of data available in today’s modern society. Scientists and researchers often need to analyze data from different sources; the observations, which only share a subset of the variables, cannot always be paired to detect common individuals. This is the case, for example, when the information required to study a certain phenomenon is coming from different sample surveys....
Percolation on dense random graphs with given degrees.
Abstract: We study the order of the largest connected component of a random graph having two sources of randomness: first, the graph is chosen randomly from all graphs with a given degree sequence, and then bond percolation is applied. Far from being able to classify all such degree sequences, we exhibit several new threshold phenomena for the order of the largest component in terms of both sources of randomness. We also provide an example of a degree sequence, for which the order of the largest component undergoes an unbounded number of...
Quantitative hydrodynamic limit and regularity for Langevin dynamics for gradient interface models.
Abstract: Lanngevin dynamics for gradient interface models are important in statistical physics due to their connection with random surfaces. It is of particular interest to understand their behavior over large-scales. In this direction a number of results have been established in the last 20 years (including the hydrodynamic limit of Funaki-Spohn and the scaling limit of Naddaf-Spencer and Giacomin-Olla-Spohn). In this talk, we will present the model, its motivations and main results. We will study a connection with the stochastic...
Branch points for (almost-)minimizers of two-phase free boundary problems.
Abstract: In this talk, we will discuss minimizers and almost-minimizers of Alt-Caffarelli-Friedman type functionals. In particular, we will consider branch points in their free boundary. This is based on recent joint work with Guy David, Max Engelstein, and Tatiana Toro.
Extremals in Hardy-Littlewood-Sobolev inequalities for stable processes.
Abstract: In this talk, we prove the existence of an extremal function in the Hardy-Littlewood-Sobolev inequality for the energy associated with an stable operator, via a concentration-compactness principle for stable processes. This result can be seen as the first step to study existence of positive solutions of the corresponding nonlocal equations with critical nonlinearities perturbed by lower order terms.
How to split the costs and charge the travellers sharing a ride? aligning system’s optimum with users’ equilibrium.
Abstract: Emerging on-demand sharing alternatives, in which one resource is utilised simultaneously by a circumstantial group of users, entail several challenges regarding how to coordinate such users. A very relevant case refers to how to form groups in a mobility system that offers shared rides, and how to split the costs within the travellers of a group. These are non-trivial tasks, as two objectives conflict: 1) minimising the total costs of the system, and 2) finding an equilibrium where each user is content with her assignment. Aligning...
El cuerpo y el aprendizaje de la multiplicación y la división a través del gesto.
RESUMEN Desde un paradigma de la cognición encarnada, la investigación de la que doy cuenta en esta ocasión buscó profundizar en la cuestión de la implicación del cuerpo y su movimiento en el aprendizaje de las operaciones de multiplicación y de división. Desde el punto de vista de la teoría de la objectivación (Radford, 2020), el acceso a esta pregunta lo provee la actividad matemática en clase. Al seno de un trabajo colaborativo con una profesora de tercer año de escolaridad de una escuela de París, elaboramos dos artefactos: el artefacto...
Language Stable Subshifts.
ABSTRACT: The language stable subshifts form a class of subshifts recently introduced by V. Cyr and B. Kra. This family contains many classical examples of subshifts, of various complexities: from positive entropy systems, such as subshifts of finite type, to low complexity systems, such as linear complexity subshifts. They are generic among the family of subshifts. In a joint work with V. Cyr and B. Kra we study some of their dynamical properties and rigidities.
