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.
The Ising model from the eyes of the Gaussian free field.
Abstract: The Ising model may be one of the most studied objects of statistical Physics. In recent years, it was shown that a proper renormalisation of a planar Ising model converges to a universal field: the continuous magnetisation field. This field is not a function but a Schwartz distribution, furthermore its statistics are not Gaussian. In this talk, we will study the properties of the Wick product of two independent magnetisation fields and show that they have the same law as a certain trigonometric function of the GFF. We will show how...
Profile of touch-down solution to a non-local MEMS model
Abstract: In this talk, I am at showing the construction of solutions with extinction (touch-down) for the equation of MEMS devices (Micro-electromechanical systems). In addition to that, we also describe the asymptotic behavior of the solution at the extinction domain.
Connecting orbits in Hilbert spaces and applications to P.D.E.
Abstract: Functional Analysis methods are often useful to solve efficiently P.D.E. problems. The idea is to view a solution of a P.D.E. as a map with values in a space of functions, and reduce the initial P.D.E. to an O.D.E. problem. I will establish a general theorem on the existence of heteroclinic orbits in Hilbert spaces. As a first application, I will present a new construction, in a more general setting, of the heteroclinic double layers (initially constructed by Schatzman). As a second application, I will show the existence of the...
Herramientas para gestión de incendios
Seminarios de la Alianza Copernicus-Chile Titulo Herramientas para gestión de incendios Expositor Jordi Brull Corporación Nacional Forestal CONAF. Fecha: lunes 19 de agosto de 2019 Hora inicio: 16:00 horas Lugar: Sala Multimedia, Centro de Modelamiento Matemático, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile. Beauchef 851, Santiago – Edificio Norte, Piso 6 Se sugiere entrar por 7 piso y bajar por la escalera (ya que este acceso no requiere tarjeta de entrada) Participación en Linea:...
Existence of infinitely many solutions for the Einstein-Lichnerowicz system
Abstract: “We will consider in this talk the Einstein-Lichnerowicz system of equations. It originates in General Relativity as a way to determine initial-data sets for the evolution problem. This system takes the form of a strongly coupled, supercritical, nonlinear system of elliptic PDEs. We will investigate its blow-up properties and show that, under some assumptions on the physics data, it possesses a non-compact family of solutions. This family of solutions will be constructed by combining toplogical methods with a...
Complexity of point-to-planar convex set distance
Abstract: In computer science, there are several equivalent ways to define a com- putable compact set in $\R^k$. One of them is the so called “locally com- putable compact set”, that is, being able to decide whether or not a given ball intersects the set – this is often referred to as the “pixel information” of the set because, loosely speaking, it allows us to know which pixels must be coloured when drawing a picture of the set on a screen. It is not hard to see that from the pixel information of a set one can compute the distance to a given...
Random walks on fractals and critical random
Resumen: The connections between random walks and electrical networks are well-known. I will describe work in this direction that demonstrates that if a sequence of spaces equipped with “resistance metrics” and measures converges with respect to the Gromov-Hausdorff -vague topology, and a certain non-explosion condition is satisfi ed, then the associated stochastic processes alsoconverge. This result generalises previous work on fractals and various models of randomgraphs in critical regimes. If time permits, I will also discuss...
The variation of maximal functions on Euclidean spaces and spheres.
Abstract: Maximal operators are central objects of study in harmonic analysis. The most classical example is the Hardy-Littlewood maximal operator (in both its centered and uncentered form) but there are also other interesting ones, for instance the ones associated to a convolution with a smooth kernel. In this introductory talk we will introduce the sub-area of harmonic analysis that studies how the variation of a maximal function behaves with respect to the initial data. We will discuss the classical results in this topic (most of...
Estados de equilibrio para una clase de productos cruzados
ABSTRACT: En esta charla mostramos la existencia y unicidad de estados equilibrio para una clase de productos cruzados asociados a ciertos potenciales naturales. Aplicamos estos resultados a los ejemplos clásicos no hiperbólicos de Abraham-Smale y Shub. Este es un trabajo en colaboración con Maria Carvalho.
