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Accueil > Séminaires > Séminaires et Groupes de travail hebdomadaires > Analyse Appliquée (AA)

Séminaire Analyse Appliquée (AA)

par Le Treust Loic, Morancey Morgan - publié le , mis à jour le

Agenda

Séminaire

  • Mardi 16 octobre 09:00-12:00 -

    Journée des nouveaux entrants à Saint-Charles

  • Mardi 23 octobre 11:00-12:00 -

    Réunion d’équipe

  • Mardi 6 novembre 11:00-12:00 - Léo Girardin

    Invasion of an empty habitat by two competitors

    Résumé : In this talk, I will present recent results obtained in collaboration
    with Adrian Lam (Ohio State University, USA). We are interested in
    the classical monostable Lotka—Volterra competition—diffusion system
    of two species and more precisely in the associated Cauchy problem when
    the initial conditions are null, or at least exponentially decaying, in
    a half-space. Thanks to a sophisticated construction of super- and
    sub-solutions, we manage to characterize completely the possible pairs
    of asymptotic spreading speeds for the two species. The main result is
    unexpected and contradicts a conjecture by Shigesada and Kawasaki : the
    second speed is not always locally determined and a form of acceleration
    is possible.

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  • Mardi 27 novembre 11:00-12:00 - Khaled SALEH - Université Claude Bernard, Lyon I

    (TBA) Khaled SALEH

  • Mardi 22 janvier 2019 11:00-12:00 - Fernando Casas - Universitat Jaume 1, Castellón, Espagne

    Splitting and composition methods with embedded error estimators

    Résumé : Splitting and composition methods are by now standard numerical
    procedures to integrate differential equations in the realm of Geometric
    Numerical Integration, where preserving whatever invariants the systems has is of paramount importance. Nevertheless, even in problems where no qualitative properties have to be preserved and/or short time integrations are required, this class of methods have shown to be an excellent option when compared with other standard integrators.
    It is in this setting where endowing splitting and composition methods with an efficient embedded error estimator could be most useful for step size control. The idea is to construct, in addition to the numerical solution, a second approximation from intermediate outputs, so that the difference is used as an estimator for the local error.
    In this talk we show how these local order schemes can be obtained at each step as a linear combination of the intermediate stages of the integrator, so that the additional computational cost required for their evaluation is almost insignificant. The estimators thus constructed are subsequently used to adapt the step size along the integration. Numerical examples show the efficiency of the procedure, in comparison with other well known embedded integration methods.

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groupe de travail

Manifestation scientifique

Descriptif
Nature Séminaire
Intitulé Analyse Appliquée
Responsables Loïc Le Treust, Morgan Morancey
Équipe de rattachement Analyse Appliquée (AA)
Fréquence Hebdomadaire
Jour-Horaire Mardi, 11h-12h
Lieu CMI, salle de séminaire (accès)
Lien -

Contacts : loic.le-treust@univ-amu.fr, morgan.morancey@univ-amu.fr

Le séminaire est un séminaire généraliste, destiné à un large public d’edpistes et analystes numériciens.
Il est donc souhaitable que les exposés ne soient pas spécialisés outre mesure, et bien sur qu’ils soient aussi clairs et pédagogiques que possible.

Les exposés doivent durer environ une heure, questions comprises.

Une liste de diffusion (modérée) pour être tenu au courant des exposés de ce séminaire : i2m-seminaire-aa@univ-amu.fr
Pour s’inscrire, contacter l’un des organisateurs.