Next seminar : Séminaire du LPTMS: Ken Sekimoto

Tuesday, May 23 2017 at 11:00:00

Coarse-Graining of Momentum Flow

Ken Sekimoto (MSC, Université Denis Diderot & Gulliver, ESPCI)

Like the energy and mass, the momentum is also a conserved quantity.  Usually, however, we pay less attention to the role played by the last  one as compared with the former ones. In the present talk, I will  discuss the three examples in which the concept of momentum flow helps  and simplifies our understanding of phenomena. First we discuss the ``adiabatic-piston'' for which the physical origin  of the non-equilibrium force has long been unclear. The consideration of  the momentum flux of both the gases and piston allows to reach the  central results in a few lines of elementary calculation, elucidating  how the non-equilibrium force emerges. Secondly we present a method of coarse-graining the overdamped dynamics  of dense cellular packing of matters.'' We show that the coarse graining  of the momentum and angular momentum fluxes leads naturally to the  Irving-Kirkwood type formula for the stress tensor irressective of the underlying dynamics. Lastly we discuss the Newton's cradle with modified repulsive laws. This  classical 1D system can show the similarity to the quantum Mössbauer  absorption and emission. By considering the momentum flow through the  cluster, we reach the coarse-grained dynamics for the center of mass coupled with an ``evanescent'' wave.

Last Highlight : Geometry and interactions in self-assembled biological systems

In honour of Françoise Livolant, the LPS (Laboratoire de Physique des Solides) and LPTMS (Laboratoire de Physique Théorique et Modèles Statistiques) are organising an international conference on geometry and interactions in self-assembled biological systems.

We will host a two days conference in Orsay, on March 23-24, 2017. Colleagues and friends are welcome.

Participants may submit their contributions to poster sessions.

Registration is free of charge but mandatory.

The conference will be held at the Institut de Physique Nucléaire (IPN), Orsay (Building 100A), close to the train station Orsay Ville on the RER B line.

The link of the conference:

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