seminar

Escuela de Educación matemática Miguel de Guzmán

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In person
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La XIV edición de la Escuela de Educación Matemática Miguel de Guzmán, que organizan la Federación de Sociedades de Profesores de Matemáticas y la RSME, se celebrará este año en Granada en las instalaciones de IMAG y en la Facultad de Ciencias Políticas y Sociología, los días 2, 3 y 4 de julio de 2025 bajo el título “Razonar para Aprender”.

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Toroidal black holes in four dimensions

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In person
description

Conferenciante: Alejandro Jímenez Cano

Fecha: Jueves, 26 de Junio a las 12:00.

Lugar: Seminario 1 IMAG

Online: https://meet.google.com/dum-nepu-pzc

Título: Toroidal black holes in four dimensions

Abstract: In this seminar, I will present the explicit construction of a black hole featuring a toroidal event horizon. The exterior geometry is divided into three regions: an outer flat region, an inner flat region with non-trivial topology and an interpolating region containing matter. We will show that the intermediate region is required to achieve a consistent matching of the spacetime geometry. Furthermore, we will prove that violations of the weak energy conditions are required in such a region to sustain the configuration under reasonable regularity assumptions.

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Sobre la existencia de superficies minimas en variedades hiperbólicas de volumen infinito

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In person
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Author : Franco Vargas-Pallete, IHES, Paris, Francia


Title : Sobre la existencia de superficies minimas en variedades hiperbólicas de volumen infinito


Location : 20 Junio 2025, Hora 12:30, Seminario 2 de IMAG


Abstract : Discutiremos dos resultados sobre existence de superficies minimas cerradas en variedades hiperbólicas de dimensión 3 y volumen infinito. Primero, provaremos que o bien toda variedade de geometria acotada posee una superficie mínina o existe un ejemplo con una foliación por superficies mínimas cerradas. En la segunda parte discutiremos existencia de superficies minimas compresibles. Basado en trabajo en colaboración con Baris Coskunuzer, Zheng Huand y Ben Lowe.


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On the fragility of laminar flow.

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In person
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Author : Marc Nualart (ICMAT)


Title : On the fragility of laminar flow.


Abstract : Steady states of the two-dimensional Euler equations generally come in infinite-dimensional families and play an important role in the long-time dynamics of generic initial data. In this talk we will review several classes of steady states, focusing on laminar flow. We will show steady laminar flow in channels or annulus are shear/radial, while on other generic domains they are structurally rare.


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¿Podemos elegir no elegir en análisis funcional?

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In person
description
  • IMAG Functional Analysis Seminar
  • Title: ¿Podemos elegir no elegir en análisis funcional?
  • By Esteban Martínez Vañó (UGR)
  • Abstract: En esta charla exploraremos las relaciones entre el axioma de elección (o versiones débiles del mismo) y los teoremas clásicos del análisis funcional mostrando que no nos queda otra opción que "elegir elegirlo".
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Teoría de juegos y EDPs

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In person
description

Author :Jorge Ruiz Cases (Universidad Autónoma de Madrid)

Title : Teoría de juegos y EDPs

Abstract : Comenzamos definiendo juegos en los que participarán una o dos personas, los cuales podrán ser deterministas o incluir azar. A cada juego le asociamos un valor que representa el beneficio que se espera lograr (en caso de dos jugadores, el que espera lograr uno de ellos). Tras tomar un límite, este valor verifica que es la solución (en sentido viscoso) de una cierta EDP asociada. Veremos cómo las reglas del juego son las que determinan el operador que gobierna la ecuación.

Una vez familiarizados con cómo plantear estos juegos, describiremos un juego determinista para dos personas, Paul y Carol. Paul pretende permanecer en un conjunto del plano todo el tiempo que pueda, mientras que Carol pretende expulsarlo de dicho conjunto. En cada turno, Paul escoge una dirección en la que va a dar un paso. Después de escoger, Carol le indica en qué sentido dará ese paso. La ecuación asociada a este juego es la de flujo por curvatura media. Observaremos como el juego no es una simple curiosidad, si no que nos permitirá obtener conclusiones que serían más complicadas de obtener a través de la propia ecuación.

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Patch Evolution in 2D Inhomogeneous Navier–Stokes.

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In person
description

Author : Paula Luna Velasco


Title : Patch Evolution in 2D Inhomogeneous Navier–Stokes


Location : Seminario 1, IMAG


Organizer : Seminario de Jóvenes Investigadores


Abstract : The motion of incompressible fluids is described by the Navier–Stokes equations, a fundamental model in mathematical physics. In two dimensions, these equations are globally well-posed for regular initial data, in contrast with the open problem in 3D. In this talk, I will focus on the inhomogeneous two-fluid system, where the fluid regions have different nonnegative densities and may exhibit a small jump in viscosity. Our main interest lies in the well-posedness of the system and in understanding the evolution and regularity of the patch boundary. I will present recent results and techniques that address the key analytical challenges of this problem. This is a joint work with Francisco Gancedo and Eduardo García-Juárez.


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Krasovskii passivity based consensus algorithms

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In person
description

Author : Michele Cucuzzella (University of Groningen)

Title : Krasovskii passivity based consensus algorithms

Abstract : In this talk a new passivity concept named Krasovskii passivity will be introduced and novel Krasovskii passivity based control techniques will be presented. Specifically, an output consensus protocol will be presented for Krasovskii passive nonlinear systems affected by external disturbances. The applicability and effectiveness of the proposed methodologies are illustrated by designing controllers for DC power networks, which are validated by experiments.

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Points of continuity in Lipschitz-free spaces

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In person
description
  • IMAG Functional Analysis Seminar
  • Title: Points of continuity in Lipschitz-free spaces
  • By Yoël Perreau (University of Tartu, Estonia)
  • Abstract: In this talk, I will present some recent results about points of (weak-to-norm) continuity in Lipschitz-free spaces. After recalling some general facts about this notion in Banach spaces, I will give some necessary conditions that an elementary molecule has to satisfy in order to be a point of continuity in a given free space. Then I will provide a complete characterization for these elements in Lipschitz-free spaces over purely 1-unrectifiable (p1u) metric spaces. If time permits, I will also discuss some examples of point of continuity in non p1u compact metric spaces.Based on a work in progress with E. Basset, T. Prochazka and T. Veeorg.
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Every nonflat conformal minimal surface is homotopic to a proper one

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In person
description

Author: Tjaša Vrhovnik


Location: Seminar Room 2 IMAG


Abstract: Given an open Riemann surface

M

, we prove that every nonflat conformal minimal immersion

M→Rn

(

n≥3

) is homotopic through nonflat conformal minimal immersions

M→Rn

to a proper one. If

n≥5

, it may be chosen in addition injective, hence a proper conformal minimal embedding. Prescribing its flux, as a consequence, every nonflat conformal minimal immersion

M→Rn

is homotopic to the real part of a proper holomorphic null embedding

M→Cn

. We also obtain a result for a more general family of holomorphic immersions from an open Riemann surface into

Cn

directed by Oka cones in

Cn

.

activity type