Noticias en español
Central limit theorems for strcutured branching processes
Abstract: Branching processes are mathematical models for populations that evolve by random reproduction: each individual lives for some time and then gives birth to new individuals, whose lives and offspring evolve independently. When such systems are enriched with spatial or structural information—allowing individuals to move, interact, or carry traits—they form infinite-dimensional stochastic processes that capture a wide range of phenomena, from cell division to particle systems. In this talk, I will discuss recent results on the central limit theorem (CLT) for a large class of such...
Read MoreThe Ramsey Number of Hypergraph Cycles.
Abstract: In 1999, Łuczak proved that the three-coloured Ramsey number of the cycle of length $n$ is less than $(4+o(1))n$, presenting a technique that, conceptually, through the use of Szemerédi’s regularity lemma, reduces the problem to that of finding the Ramsey number of a connected matching. Ever since then, Łuczak’s method has been applied successfully in many results. There are many natural ways to generalize cycles for $k$-uniform hypergraphs. In this talk, we first present a brief survey of the Ramsey numbers of Berge, loose, and tight cycles. Then we examine the use...
Read MoreFingerprinting Techniques for Lower Bounds in Differential Privacy and a New Fingerprinting Lemm.
Abstract: Analyzing sensitive data presents a fundamental dilemma: how can we extract population-level insights while protecting individual privacy? Differential Privacy (DP) provides a rigorous mathematical framework to address this challenge, offering formal guarantees against sensitive data exposure. Beyond its widespread adoption in practice, DP has revealed surprising connections to various fields like online learning, machine learning generalization, and robust statistics. In this talk, I’ll provide a brief introduction to the core ideas of differential privacy. I will then give...
Read MoreWeakly aperiodic Wang subshifts with minimal alphabet size on free groups.
RESUMEN Motivated by the work of E.Jeandel and M.Rao [1], where the authors establish the minimal amount of ℤ²-Wang tiles needed to produce a nonempty aperiodic ℤ²-Wang subshift to be 11, as well as the article of Piantadosi [2] which develops some aspects of symbolic dynamics on free groups related to aperiodicity, we study Wang subshifts on (k). We obtain that the minimal amount of Wang tiles needed to generate a nonempty weakly aperiodic Wang subshift on (k) is 3, and characterize every such example.
Read MoreThe Fractional Anisotropic Calderón Problem
RESUMEN: We will discuss some recent progress on the anisotropic Calderón problem for the fractional Laplacian.
Read MoreSecretary Problems and Combinatorial Optimal Stopping.
Abstract: Secretary problems constitute a classical setting of online decision-making, where discrete elements arrive in uniformly random order, reveal their weight, and must be accepted or rejected irrevocably, with the aim of maximizing a given function over the selected set. In the most general form of the problem, we are given a combinatorial feasibility constraint (e.g. a matroid) and the selected set has to be feasible with respect to that constraint. In such problems, the objective is to design algorithms which guarantee a multiplicative factor approximation with respect to the...
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