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 joint transitivity property.
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Second-order dynamical systems associated with a class of quasiconvex functions.
Abstract: In this talk, we examine second-order gradient dynamical systems for smooth strongly quasiconvex functions, without assuming the usual Lipschitz continuity of the gradient. We establish that these systems exhibit exponential convergence of the trajectories towards an optimal solution. Furthermore, we extend our analysis to the broader quasiconvex setting by incorporating Hessian-driven damping into the second-order dynamics. Finally, we demonstrate that explicit discretizations of these dynamical systems result in gradient-based...
Spread measures on perfect matchings in regular pairs.
Abstract: The notion of spread distributions on copies of a given graph (or family of graphs) has played a crucial role in recent developments in probabilistic combinatorics, particularly in studying thresholds in random graphs. In this talk, I will show how to construct a spread distribution on perfect matching in regular pairs, which can be used together with the regularity lemma to find well-behaved embeddings of sparse graphs.
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...
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.
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...
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...
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...
