Noticias en español
Powers of Hamilton cycles in directed and oriented graphs.
Abstract: The P\’osa–Seymour conjecture determines the minimum degree threshold for forcing the $k$th power of a Hamilton cycle in a graph. After numerous partial results, Koml\’os, S\’ark\”ozy and Szemer\’edi proved the conjecture for sufficiently large graphs. We focus on the analogous problem for digraphs and for oriented graphs. For digraphs, we asymptotically determine the minimum total degree threshold for forcing the square of a Hamilton cycle. We also give a conjecture on the corresponding threshold for $k$th powers of a Hamilton cycle more...
Read MoreBlow-up Analysis of Large Conformal Metrics With Prescribed Gaussian And Geodesic Curvatures
Abstract: In this talk, we consider a compact Riemannian surface (M,g) with nonempty boundary and negative Euler characteristic. Given two smooth non-constant functions f in M and h in the boundary of M with max f = max h = 0, under a suitable condition on the maximum points of f and h, we prove that for sufficiently small positive constants λ and μ, there exist at least two distinct conformal metrics g_{λ,μ}=e^{2u_{μ,λ}}g and g^{λ,μ}=e^{2u^{μ,λ}}g with prescribed sign-changing Gaussian and geodesic curvature equal to f+μ and h+λ, respectively. Additionally, we employ the method Borer et...
Read MoreA comparison theorem for integrated stochastic Volterra models with application to the modelling of Lagrangian intermittency in turbulence.
Resumen: We introduce a stochastic model for the Lagrangian velocity and dissipation of a turbulent flow, which takes the form of an integrated Volterra process, as already proposed in the litterature. In order to understand how to reproduce the multifractal behaviours predicted by the Kolomogorov refined theory, we propose a way to compare the effects of different Volterra kernels on the statistics of the integrated process. Since Volterra processes are not Markovian, we use the martingale approach and the functional Itô formula from [Viens, Zhang 2019], combined with the path-dependent...
Read MoreBidding problems in European deregulated electricity markets.
Abstract: In this talk, we consider a bidding problem in European deregulated electricity markets. The goal of this problem is to maximize the profit of a Generation Company (GC) by choosing the best possible bids to propose to a Market Operator (MO) whose tasks is to minimize the daily price of electricity for the retailers. This problem has many challenging features to consider such as unit commitment for the GC, a market clearing system for the MO and demand and productions capacities are subject to increasing uncertainty due to renewable energies. Most studies in the literature try to...
Read MoreEstimación de fuentes y sumideros de metano a escala global a través de la asimilación de datos satelitales en un sistema de inversión atmosférica.
Read MoreMinimal configurations for Frenkel-Kontorova model on a quasicrystal.
RESUMEN: The Frenkel-Kontorova model is a physical model that is mathematically simple to describe and universal in the sense that it can be used to describe several underlying physical concepts. It was originally introduced in 1938 to represent the structure and dynamics of a crystal lattice in the vicinity of a dislocation core. It models a chain of classical particles coupled to their neighbors and subjected to an external potential. In this talk, I will present an overview of some known properties and open questions concerning equilibrium configurations when the external potential is...
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