Mardi 27 Juin à 11h30
Zdzislaw Burda (Jagellonian University, Krakow) : Random Matrix Theory : From fundamental physics to engineering
Random matrix theory was originally formulated by Eugene Wigner in
the fifties of the last century in the studies of quantum multi-body
systems. Thinking in terms of random matrices was a revolutionary
idea which provided a completely new way of approaching problems
on the junction of quantum and statistical physics.
The importance of the theory was not immediately recognized by the
community. For many years the theory was in the state of hibernation.
A break-through came with the book by Mehta and the seminal paper
by Brezin, Itzykson, Parisi and Zuber. Ever since random matrix
theory has been continuously attracting a great attention of
a broader and broader community of researchers. Today, it provides
a universal language and a way of thinking which applies to a
wide spectrum of problems ranging from fundamental problems in
number theory, string theory, gravity, QCD, quantum chaos, quantum
transport, information theory, combinatorics to applied ones in
biophysics, econophysics, quantitative finance and telecommunication.
In the talk we will discuss some applications of this theory.
Mardi 22 Novembre à 11h30 (SEMINAIRE ANNULE)
Luigi Del Debbio (University of Edinburgh) :
Lattice QCD with two light quarks
Simulations of lattice QCD with two quarks in the Wilson formulation provide a theoretically robust framework to study the nonperturbative properties of strong interactions. Due to recent progress in the algorithms, numerical simulations can now access lighter quarks, while keeping the lattice spacing small and the volume sufficiently large. I will review the algorithmic progress and present results that show how lattice QCD makes contact with chiral perturbation theory.
Mercredi 16 Novembre à 11h
A. Martin (CERN) :
On the stability of four feet tables
We prove that a perfect four-feet square table, posed in a continuous irregular ground with a local slope of at most 15 degrees, can be put in equilibrium on the ground by a "rotation" of less than 90 degrees. We also discuss the case of non-square tables and make the conjecture that equilibrium can be found if the four feet are on a circle.
Mardi 18 Octobre à 11h30
V. Rivasseau (LPT, Orsay) : Rapport sur le récent symposium Responsabilités scientifiques en matière d’armement
Le symposium Science in the Service of War and the Responsibility of scientists s’est tenu a l’ENS du 20 au 21 septembre 2005. Certains d’entre vous ont regretté de n’avoir pu y participer. V. Rivasseau, un des organisateurs, propose d’en faire un résumé suivi d’une discussion informelle.