2017-2018 ICFP seminar Program

Accès rapides

Accès rapides

Prochain Séminaire de la FIP :
Accéder au programme

Retrouvez toutes les informations pour vos stages :
Stages L3
Stages M1 ICFP
Stages M2 ICFP

Actualités : Séminaire de Recherche ICFP
du 6 au 10 novembre 2017 :

Retrouvez le programme complet

Emploi du temps 2017-2018 :
Emploi du temps L3
Emploi du temps M1 ICFP
Emploi du temps M2 ICFP

Contact - Secrétariat de l’enseignement :
Tél : 01 44 32 35 61
enseignement@phys.ens.fr

$  0

The seminar takes place on Tuesday, at 5:15pm.

 September 26 : Erwan Allys

Seminar room : CONF4 (salle E244) - 24 rue Lhomond

Laboratoire de Radioastronomie, ENS Paris
Probing Grand Unified Theories with topological defects in Cosmology

Cosmic strings are linear topological defects which are expected to form during the spontaneous symmetry breaking of a Grand Unified Theory in the early universe. They could allow us to observationally probe particle physics up to energies of 10^16 GeV. The idea of this talk is to explain what are cosmic strings, and why we expect them to be formed in the standard cosmological scenario, before to discuss the current challenges linked with their observation. In a first part, we will present the concept of local symmetries in particles physics, the Standard Model, and explain why Grand Unified Theories are attractive models to describe physics at very high energies. In a second part, we will present in a broad manner the concepts of topological defect, considering both the cases of domain walls and cosmic strings/vortex lines. We fill finally discuss the formation and evolution of a cosmological lattice of cosmic strings, as well as the associated observational studies.

 October 10 : Jean-Francois Rupprecht

Seminar room : Amphi Jaurès - 29 rue d’Ulm

Mechanobiology Institute, National University of Singapore
Grab-and-pull : from motors pinching to nuclear shaking and organ shaping

Cells sense the rigidity of their environment through local pinching exerted by bundles of myosin motors contracting over actin filaments. Recent experiments have shown that the motors within these bundles are surprisingly efficient, exerting forces that are way larger than the classically reported value of 5pN/motor. We interpret this high force generation based on a new molecular motor model, whereby a two-state potential describes the interaction of the myosin head over the two strands of the actin filament. Our mean-field description predicts that the collective dynamics of motors has features of a first order transition. The dynamics of motors has a strong stochastic component, which has been shown experimentally to lead to cell-scale stress fluctuations. We investigate the role of these fluctuations on the stochastic dynamics of an inclusion embedded in an active viscous gel. We show that, in non-equilibrium systems, stress fluctuations give rise to an effective attraction towards the boundaries of the confining domain. We apply our result to the dynamics of deformations of the cell nucleus and we demonstrate the appearance of a fluctuation maximum at a critical level of myosin motor activity, in agreement with experiments. Moving further to larger length scales, we consider the role of myosin motor contractility in organ formation. We model how, during embryogenesis, muscle segments of the zebrafish acquire their characteristic V-shape.

 October 24 : Master 1 internships

Seminar room : Amphi Jaurès - 29 rue d’Ulm

 November 7 : Joshua McGraw

Seminar room : Amphi Dussane - 45 rue d’Ulm

Département de Physique, ENS Paris

 November 21 : Bruno Laburthe-Tolra

Seminar room : Amphi Jaurès - 29 rue d’Ulm

Laboratoire de Physique des Lasers, Université Paris 13

 December 5 : Kenneth Maussang

Seminar room : Amphi Jaurès - 29 rue d’Ulm

Institut d’Électronique et des Systèmes, Université de Montpellier

 December 19 :

Seminar room : Amphi Jaurès - 29 rue d’Ulm

Accès rapides

Prochain Séminaire de la FIP :
Accéder au programme

Retrouvez toutes les informations pour vos stages :
Stages L3
Stages M1 ICFP
Stages M2 ICFP

Actualités : Séminaire de Recherche ICFP
du 6 au 10 novembre 2017 :

Retrouvez le programme complet

Emploi du temps 2017-2018 :
Emploi du temps L3
Emploi du temps M1 ICFP
Emploi du temps M2 ICFP

Contact - Secrétariat de l’enseignement :
Tél : 01 44 32 35 61
enseignement@phys.ens.fr