Monday, Sep 03, 2018
14h00 Séminaire SCOPI ParisSaclay
Séminaire SCOPI ParisSaclay
Orme des Merisiers  Amphi Claude Bloch, Bât. 774 Orme des Merisiers
(TBA)
The research performed at the IPhT aims at better understanding the laws which govern our universe and its organisation. It encompasses most of the great subjects of modern theoretical physics:
The IPhT comprises about fifty permanent physicists (2/3 CEA, 1/3 CNRS), about thirty PhD students and postdocs, assisted by a support staff of about ten people. The IPhT also hosts permanently many short term visitors.
The popularscience magazine "La Recherche" presents this month (vol 537538, JulyAugust 2018) a special issue devoted to complex systems in which our Institute is well represented. Among the articles, Lenka Zdeborová and Florent Krzakala discuss statistical physics approach to extract relevant information from large datasets, and Marc Barthelemy presents physical approaches to model urban systems.


C. Pepin, 20180710

The 23th Rencontres Claude Itzykson "Statistical Physics of Disordered and Complex Systems: A Tribute to Cirano De Dominicis" took place at IPhT on June 4 – 6, 2018. Our friend Cirano passed away in April 2017. The conference provided a unique opportunity to gather together former collaborators, colleagues and friends of Cirano De Dominicis, as well as younger researchers, who made significant contributions in the fields of Statistical Physics, in which Cirano had major impact: Quantum ManyBody problem, dynamics of out of equilibrium systems, spin glasses and disordered systems. Speakers included: Roger Balian, Andrea Crisanti, Bernard Derrida, Philippe Di Francesco, Irene Giardina, Francesco Guerra, Bertrand Halperin, Henk Hilhorst, Imre Kondor, Marc Mézard, Michael Moore, Peter Mottishaw, Giorgio Parisi, Luca Peliti, Peter Young, Annette Zippelius Many thanks to the organizing committee: Giulio Biroli, Edouard Brézin, Henri Orland, and Laure Sauboy (Secretary) Webpage: https://indico.in2p3.fr/event/17044/ Videos of the talks: IPhTTV on YouTube 

F. David, 20180626

The idea that physics at low energy, i.e. large distances, can be described in terms of light degrees of freedom alone is one of the most satisfactory organizing principle in physics, which goes under the name of Effective Field Theory (EFT). The effect of shortdistance ultraviolet (UV) dynamics is systematically accounted for in the resulting infrared (IR) EFT by integrating out the heavy degrees of freedom, which generate an EFT built of infinitely many local operators. Yet, EFT’s are predictive even when the UV dynamics is unknown, because in practice only a finite number of operators contributes, at a given accuracy, to observable quantities. The higher the operator dimension, the smaller the effect at low energy.
Remarkably enough, extra information about the UV can always be extracted if the underlying Lorentz invariant microscopic theory is unitary, causal and local. These principles are encoded in the fundamental properties of the Smatrix such as unitarity, ... 

C. Pepin, 20180517

L’universalité des matrices aléatoires: un article de Bertrand Eynard dans Pour la science
"Trous de ver, la porte des étoiles": écouter Monica Guica sur Radio France
Nick Warner awarded an ERC Advanced grant to work at IPhT
"Morphogenesis of Spatial Networks": a book by Marc Barthelemy
2018 Beg Rohu summer school: Deep Learning and Statistical Physics