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.
Variational Approach for the Singular Perturbation Domain Wall Coupled System.
Abstract: In this talk, I will present results on a singular perturbation problem modeling domain walls. I will discuss the existence of solutions both when the perturbation parameter is non-zero and when it is set to zero (Thomas-Fermi approximation), demonstrating their continuous connection as the parameter approaches zero. Finally, I will show that the behavior of one of the variables can be modeled by a Painlevé II equation in the limit, by the use of an appropriate change of variables.
An overview of some coloring parameters for (n,m)-graphs.
Abstract: Graph coloring is one of the most famous problems in graph theory. The most natural question to ask in this framework is whether or not a given family of graphs has a finite chromatic number. As graph homomorphisms generalize coloring, we study the notion of homomorphisms for (n,m)-graphs. Due to their various types of adjacencies, the (n,m)-graphs manage to capture complex relational structures and are useful for mathematical modeling. For instance, the Query Evaluation Problem (QEP) in graph databases, the immensely popular...
Singular perturbation method for stability of infinite-dimensional systems.
RESUMEN: Coupled systems appear everywhere in complex models and in some cases there are different time scales involved. The coupling and the scales make this kind of system very difficult to study from theoretical and computational viewpoints. One hopes that some particular properties of the system could be studied through simpler uncoupled systems. This is what the singular perturbation method (SPM) does concerning stability properties. The SPM approach has been introduced for ordinary differential equations and can also be applied for...
A Remotely Sensed View of Water Ecosystems.
Los grandes sistemas fluviales y sus hábitats, como las llanuras aluviales y los humedales, son cruciales para las necesidades humanas, pero están experimentando una pérdida significativa de biodiversidad y una disminución en los servicios ecosistémicos debido a amenazas como la construcción de represas, el cambio climático y los cambios en el uso del suelo. Para conservar estos ecosistemas, es vital comprender sus funciones e interacciones. La teledetección, combinada con métodos tradicionales, ofrece herramientas valiosas para monitorear y...
Dinámica no autónoma generalizada a través de morfismos de grupoides.
RESUMEN En esta charla explico cómo extender las nociones de dinámica no autónoma a grupos arbitrarios, a través de morfismos de groupoides. Esto también presenta una generalización de los sistemas dinámicos clásicos y de las acciones de grupos. Introduzco la estructura de cotraslaciones, como un tipo específico de morfismo de groupoide, y establezco una correspondencia entre cotraslaciones y skew-products. Presentamos aplicaciones de las cotraslaciones a ecuaciones no autónomas, tanto en diferencias como diferenciales. También...
Convergence Analysis of Davis-Yin Splitting via Scaled Relative Graphs.
Abstract: Davis-Yin splitting (DYS) has found a wide range of applications in optimization, but its linear rates of convergence have not been studied extensively. The scaled relative graph (SRG) simplifies the convergence analysis of operator splitting methods by mapping the action of the operator onto the complex plane, but the prior SRG theory did not fully apply to the DYS operator. In this work, we formalize an SRG theory for the DYS operator and use it to obtain tighter contraction factors.
Gaussian curvature for LQG surfaces and random planar maps.
Abstract: Liouville quantum gravity is a canonical model for random surfaces conjectured to be the scaling limit of various planar maps. Given that curvature is a central concept in Riemannian geometry, it is natural to ask whether this can be extended to LQG surfaces. Here, we define the Gaussian curvature for LQG surfaces (despite their low regularity) and study the relations with its discrete counterparts. We conjecture that this definition of Gaussian curvature is the scaling limit of the discrete curvature, we prove that the discrete...
Crecimiento de la derivada para difeomorfismos del intervalo (con todos sus puntos fijos parabólicos)
RESUMEN:Hace un par de décadas, Polterovich y Sodin probaron un sorprendente resultado: para un difeomorfismo de clase C² del intervalo con todos sus puntos fijos parabólicos, el crecimiento de la derivada es a lo más cuadrático. En esta charla, comenzaremos comentando aspectos sobre la demostración de este resultado. Luego, estableceremos nuestro resultado principal, el cual ofrece un mejoramiento del resultado de Polterovich y Sodin al estimar exactamente el crecimiento de la derivada. Hablaremos brevemente de las herramientas utilizadas en...
