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.
Strategyproof mechanisms without money for independence systems.
Abstract: We consider mechanisms without money for combinatorial independence systems. We are given an independence system where the ground set of items is partitioned into sets owned by strategic agents. Each item has a weight that is the private information of the agent owning it. A mechanism takes an independence system, the weights, and the partitioning as input and returns an independent set; it is strategyproof if no agent can increase the total weight of their items in the solution by reporting lower weights of their items to the...
Central limit theorems for structured branching processes
Resumen: In this talk I will discuss recent progress on central limit theorems for supercritical branching Markov processes in infinite-dimensional settings. The class of processes under consideration allows for spatial dependence and branching mechanisms that need not be local. A key feature of our approach is that it only requires a fourth moment condition together with exponential convergence of the mean semigroup in a weighted total variation norm. This assumption is mild in that it does not rely on symmetry or detailed spectral...
Deformation to positive scalar curvature on complete manifolds with boundary.
Abstract: We will talk about conformal deformations of the scalar curvature and mean curvature on complete Riemannian manifolds with boundary. We establish sufficient conditions for the existence of conformal deformations to complete metrics with positive scalar curvature and mean convex boundary.
New advances on the regularity of solutions to equations ruled by the $\infty$-Laplacian
Abstract: The theory of regularity, beyond its theoretical relevance in the study of partial differential equations, plays a central role in modeling various natural phenomena, including those arising in biology, materials science, fluid dynamics, and mathematical physics. In this talk, we will present results concerning the regularity of solutions to equations governed by the infinity Laplacian, with particular emphasis on infinity-harmonic functions, as well as recent advances on singular problems and Hénon-type...
Two-Edge Connectivity via Pac-Man Gluing.
Abstract: We study the 2-edge-connected spanning subgraph (2-ECSS) problem: Given a graph $G$, compute a connected subgraph $H$ of $G$ with the minimum number of edges such that $H$ is spanning, i.e., $V(H) = V(G)$, and $H$ is 2-edge-connected, i.e., $H$ remains connected upon the deletion of any single edge, if such an $H$ exists. The $2$-ECSS problem is known to be NP-hard. In this work, we provide a polynomial-time $(\frac 5 4 + \varepsilon)$-approximation for the problem for an arbitrarily small $\varepsilon>0$, improving the previous...
Canonical Ramsey numbers for partite hypergraphs.
Abstract: Ramsey’s theorem states that for sufficiently large n, any r-colouring of the edges of the complete k-uniform hypergraph on n vertices contains a monochromatic copy of the complete k-uniform hypergraph on t vertices. Erdős and Rado generalised this result to an unbounded number of colours. They characterised all canonical colour patterns that are unavoidable in edge colourings of sufficiently large complete hypergraphs. We consider quantitative aspects of this result. For Erdős and Rado’s theorem, both the lower and...
Nonlinear Reach Controllability in Two-Dimensional Simplices.
Abstract: This talk addresses the problem of constrained reach controllability in two dimensions. Considering a nonlinear controlled dynamics (given by an ODE) within a two-dimensional simplex, the goal is to design a feedback control—either continuous or piecewise continuous—that can steer any point inside the simplex to the outside, subject to the additional restriction that exit is only allowed through one of its faces. We will present sufficient conditions to determine whether a given control constitutes a solution, as well as a result...
Stochastic processes, transport of mass, and functional inequalities.
Resumen: Functional inequalities have proven to be a ubiquitous tool in mathematics, especially in probability theory. For example, they are closely related to the concentration of measure phenomenon, and they help quantify the rate at which ergodic Markov processes converge to equilibrium. Prominent examples of those inequalities include the families of logarithmic Sobolev, Poincaré, and transport-entropy inequalities. In the first part of the talk, I will provide an introduction to this topic, highlighting the classical examples, results,...
Abstract: For a family of graphs H, a graph G is H-free if no induced subgraph of G is isomorphic to a graph in H. In this talk, I will present a new decomposition theorem and coloring algorithm for(2P_3,C_4,C_6)-free graphs. I will also give some background on Truemper configurations (thetas, pyramids, prisms, and wheels) and on proving decomposition theorems in general
