IPhT

Selon Miguel Zumalacarregui, de l'IPhT et son collaborateur Uros Seljak, la matière noire ne peut être intégralement constituée de trous noirs de masse supérieure à un centième de la masse solaire. Il faut donc aussi chercher du côté des particules élémentaires pour démasquer la matière noire!

We are happy to learn that Michel Gaudin has been awarded the 2019 Dannie Heineman Prize for Mathematical Physics, together with Bill Sutherland (U. of Utah) and F. Calogero (U. di Roma La Sapienza), for their "... profound contributions to the field of exactly solvable models in statistical mechanics and many body physics, in particular the construction of the widely studied Gaudin magnet and the Calogero-Sutherland, Shastry-Sutherland, and Calogero-Moser models." This prize was established in 1959 by the Heineman Foundation for Research, Educational, Charitable, and Scientific Purposes, Inc., and is administered jointly by the American Physical Society and the American Institute of Physics. It recognizes outstanding publications in the field of mathematical physics. Michel Gaudin entered CEA in 1956 and is one of the "grands anciens" of what is now IPhT.

Bertrand Eynard (IPhT) has been awarded an ERC Synergy grant, "Recursive and Exact New Quantum Theory", together with J.E. Andersen (QGM, Aarhus University, DK), B. Eynard (IPhT), Mr. Kontsevich (IHES, Bures-sur-Yvette) and M. Mariño (UNIGE, Geneva, CH). Two other IPhT researchers are involved in this project. The Synergy Grants aim to establish collaborations between several researchers in different institutes on a common program. The goal of the ReNewQuantun program is to build new foundations for quantum field theory, beyond perturbation theory, by using advanced geometric and topological methods (topological recursion, geometric recursion, resurgence theory, non-linear Riemann-Hilbert methods, Fukaya categories, topological string theories, mirror symmetry, etc.). This program should open new avenues for exploring the relations between gravitation and quantum mechanics, and for incorporating it into unified theories of fundamental interactions.

Stéphane Lavignac (IPhT) vient de publier avec Antoine Kouchner, directeur du laboratoire Astroparticule et Cosmologie de l’Université Paris-Diderot, un livre de vulgarisation sur les neutrinos : « A la recherche des neutrinos – messagers de l’infiniment grand et de l’infiniment petit », collection « Quai des Sciences », éditions Dunod. Dépourvus de charge électrique, dotés de masses très petites et interagissant très faiblement avec la matière, les neutrinos comptent parmi les particules élémentaires les plus mystérieuses. Introduits presque en catimini par Wolfgang Pauli en 1930, dans une tentative désespérée de sauver le principe de conservation de l’énergie, les neutrinos n’ont eu de cesse d’intriguer les physiciens.

L'Institut de Physique Théorique organise une journée scientifique sur le thème "Phénomènes hors d’équilibre" le mardi 2 octobre de 9h30 à 17h à l'amphithéâtre Claude Bloch. Le but de cette rencontre est d'illustrer et de mettre en contact "qui fait quoi au CEA" en matière de physique des phénomènes hors d’équilibre. Nous invitons tous les scientifiques ayant un intérêt pour cette thématique à participer.

The popular-science magazine "La Recherche" presents this month (vol 537-538, July-August 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.

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 short-distance 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.

IPhT will host a 4-week program on topological phases in condensed matter. The goal of this program, dubbed TopMat, is to gather some experts in the field interacting topological phases, such as fractional quantum Hall states or quantum spin liquids in magnets, to discuss the latest theoretical and experimental developments, and to favor informal discussions and new collaborations. This program will welcome more than 30 invited participants in total, most of them from abroad and staying for more than one week. A preliminary list of participants is available on https://topmat.sciencesconf.org/. The detail scientific program, with about two talks per day (open to every one), will be available soon. Scientific coordinators : Thierry Jolicoeur (LPTMS, Université Paris-Sud), Philippe Lecheminant (LPTM, Université de Cergy-Pontoise) and Grégoire Misguich (IPhT, CEA Saclay). TopMat is organized and funded in the framework of the project 'PSI2' of the Université Paris-Saclay.

Nicholas Warner, Professor of Physics, Astronomy and Mathematics at USC, has just been awarded an ERC Advanced grant to work at IPhT for the duration of this fellowship. Already a visitor and regular collaborator of IPhT, Nick will arrive January 2019 to work on his program "QBH Structure: The Quantum Structure of Black Holes and the Recovery of Information" with IPhT researchers. He will bring his creativity, his energy and his enthusiasm to the CEA and the whole theoreticians community on this fundamental and fast growing subject, at the interface between fundamental interactions, cosmology and quantum information! Congratulations and welcome, Nick!

"Provides the first comprehensive presentation of state-of-the-art knowledge about spatial networks" This book develops a morphodynamical approach of spatial networks with a particular emphasis on infrastructure networks such as streets, roads and transportation networks (subway, train). The author presents the mathematical tools needed to characterize these structures and how they evolve in time. The book discusses the most important empirical results and stylized facts, and will present the most important models of spatial networks. The target audience primarily comprises research scientists interested in this rapidly evolving and highly interdisciplinary field, but the book may also be beneficial for graduate students interested in large networks.