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Les événements de septembre 2023

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Séminaire

  • Analyse Numérique et Calcul Scientifique

    • Jeudi 7 septembre 11:00-12:00 - Thanh Trung Le - LmB

      Séminaire d’Analyse Numérique et Calcul Scientifique

      Résumé : Numerical challenges for the understanding of localised solutions with different symmetries in non-local hyperbolic systems
      We consider a one-dimensional nonlocal hyperbolic model introduced to describe the formation and movement of self-organizing collectives of animals in homogeneous 1D environments. Previous research has shown that this model exhibits a large number of complex spatial and spatiotemporal aggregation patterns, as evidenced by numerical simulations and weakly nonlinear analysis. In this study, we focus on a particular type of localised patterns with odd/even/no symmetries (which are usually part of snaking solution branches with different symmetries that form complex bifurcation structures called snake-and-ladder bifurcations).
      To numerically investigate the bifurcating solution branches (to eventually construct the full bifurcating structures), we first need to understand the numerical issues that could appear when using different numerical schemes. To this end, in this study, we consider ten different numerical schemes (the upwind scheme, the MacCormack scheme, the Fractional-Step method, and the Quasi-Steady Wave-Propagation algorithm, combining them with high-resolution methods), while paying attention to the preservation of the solution symmetries with all these schemes. We show several numerical issues in our study. First, we observe the presence of two distinct types of numerical solutions (with different symmetries) that exhibit very small errors, which might initially suggest that we have reached a steady-state solution, but this is not the case. This also implies an extremely slow convergence. Second, in some cases, none of the investigated numerical schemes converge, posing a numerical analysis challenge. Lastly, we have discovered that the choice of the numerical schemes, as well as their corresponding parameters such as time-space steps, exert a significant influence on the type and symmetry of bifurcating solutions. We conclude that if we want to construct bifurcation diagrams for these localised solutions with different symmetries, the resulting bifurcations may vary when different numerical schemes and/or corresponding parameters are employed.

      Lieu : Salle 316 - LmB

      Article

  • Analyse Fonctionnelle

    • Mardi 12 septembre 13:45-15:00 - Christian Le Merdy - LMB

      Multiplicateurs de Fourier isométriques

      Résumé : TBA

      Lieu : Salle 316 B bis (3ème étage) - Laboratoire de Mathématiques de Besançon (LmB), Campus de la Bouloie, bâtiment Métrologie B, Université de Franche-Comté, 16 route de Gray, 25030 Besançon

      Article

    • Mardi 26 septembre 13:45-15:00 - Deepak Gothwal - Indian Statistical Institute, Kolkata, Inde

      TBA

      Résumé : Uniform Mazur Intersection Property, Moduli
      and Uniform w*-Dentability
      In this talk, we discuss an important characterisation of the Uniform
      Mazur Intersection Property (UMIP) in terms of w*-semidenting points.
      Based on the modulus of uniform w*-dentability, a modulus of the UMIP
      is obtained. We discuss two different notions of uniform w*-dentability
      and connect these to a nice geomteric property and observe that super-
      reflexivity is weaker than these properties, thus taking forward the con-
      nection between denting points and LUR renorming.

      Lieu : Salle 305Bbis (3ème étage) - Laboratoire de Mathématiques de Besançon (LmB), Campus de la Bouloie, bâtiment Métrologie B, Université de Franche-Comté, 16 route de Gray, 25030 Besançon

      Article

Colloque / Journée

  • Analyse Fonctionnelle

    • Du 19 au 22 septembre -

      Æsy to define, Hard to analyse : First conference on Lipschitz free spaces

      Lieu : Besançon, Centre Diocésain

      Article

Réunion

  • LMB

    • Jeudi 14 septembre 12:30-13:30 -

      Réunion du LmB ouverte au Département

      Lieu : LmB, salle 316B

      Article

  • LMB

    • Jeudi 21 septembre 15:00-16:00 -

      Réunion du LmB ouverte au Département

      Lieu : LmB, salle 316B

      Article

Soutenance

  • Doctorant

    • Vendredi 8 septembre 11:00-13:00 -

      Soutenance de thèse de Purbayan CHAKRABORTY

      Lieu : LmB, salles 316B et 316Bbis

      Article

  • Doctorant

    • Mardi 26 septembre 14:00-17:00 -

      Soutenance de thèse Hussein AL BAZZAL

      Lieu : Institut FEMTO, Amphi Gagnepain

      Article

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