EnigmassLaboratoires d'Excellence CIPHEACentre International de Physique des Hautes Energies et d'Astrophysique Latest Publications
Présentation du Laboratoire d'Annecy-le-Vieux de Physique Théorique (LAPTh)Le LAPTh est une unité mixte de recherche (UMR 5108) CNRS-INP/Université de Savoie. Le laboratoire est situé à Annecy-le-Vieux, 5km du centre d'Annecy et à 40km du CERN et de Genève. Les activités du LAPTh sont centrées autour de trois grands thèmes de recherche:
ActualitésLectures on Amplitudes and SymbolsWith the advent of the LHC and the need for ever increasing accuracy, techniques in loops calculations have witnessed tremendous progress borrowing from highly complex mathematical structures and improving and adapting these structures. A very recent development concerns the use of symbols. Giorgios Papathanasiou will introduce some of these concepts starting from an elementary exposition of how these objects appear from the integrals one encounters in the evaluation of scattering amplitudes beyond tree-level. There will be 4 lectures: 1: Analytic structure of scattering amplitudes and Feynman integrals. Algebraic and transcendental functions. Classical polylogarithms. 2: Multiple polylogarithms (MPL): Integral and Series representations. Shuffle and quasi-shuffle algebras. 3: The symbol map. Properties. Integrability condition. Application: Resolving identities among MPLs and simplifying expressions. 4: (Optional) Advanced topics: The Hopf algebra of MPLs and the coproduct. Bootstrapping amplitudes. Expanding the symbol. Graspa 2015Undergraduate Summer School in Particle and Astroparticle Physics of Annecy-le-Vieux, July 16-22 2015 The school aims at introducing Particle Physics and Astroparticle physics to 4th and advanced 3rd year physics students from anywhere in the world. The most recent research topics and results in these fields will be presented. The school consists of 4 days of lectures on LHC Physics, Neutrinos, Heavy Flavours, Astroparticle Physics and Gravitational Waves. Computational tools for these fields will also be introduced during a hands-on session. The students will be immersed in an international research atmosphere. They will be able to spend time and discuss at length with scientists working in the field. Courses will be in English. No background knowledge on the topics covered beyond a popular science level is assumed. A strong background in Quantum Mechanics is expected, however.
A maximum of 30 students will be admitted. PhysTeV Les Houches 2015In a few weeks the high energy physics team will be going to Les Houches. We will be overseeing the 9th session of the LH PhysTeV. This session will coincide with the first beams at the LHC which will soon be running at 13TeV. The highlight of the 2015 Les Houches Edition is to take full advantage of the data that has been collected at the LHC so far and prepare for the future runs. The Workshop will devote particular attention to:(i) Higgs physics, and how it shapes our view on the mechanism of electroweak symmetry breaking; (ii) related searches for New Physics and (iii) progress in new techniques for the calculations and simulation of Standard Model processes. These activities will be conducted in close connection with the development and improvements of related theory tools, in particular of Monte-Carlo event generators. The Workshop proper runs over one year, including two meetings in Les Houches in the month of June, and exchanges and collaborations before and after the meetings. The meetings in Les Houches will consist of two sessions: Session I: 1-10 June 2015with emphasis on SM-related issues Session II: 10-19 June 2015 with emphasis on New-Physics searches A course on Nonequilibrium ProcessesKirone Mallick from the Institut de Physique Théorique (IPhT) CEA Saclay is giving a set of lectures describing recent advances in systems far from equilibrium. After a review of equilibrium thermodynamics, the lectures will introduce the fascinating identities of Jarzinski and Crooks which quantify the transient violations of the second principle. This will be followed by the fluctuation theorem of Gallavoti-Cohen. Here is the exciting programme 1. Review of statistical physics: Equilibrium versus Non-equilibrium. Dynamics, Detailed Balance and Time-reversal. A Possible solution to the Lithium problem?Big Bang Nucleosynthesis (BBN) is an admirable achievement of the standard cosmological model as it very precisely predicts the amount of the most abundant elements, in particular hydrogen and helium. On close inspection the picture is marred by a long standing and annoying problem. Though its abundance is extremely small, the standard predicted amount of lithium is about a factor 3 larger than what observed in some metal-poor stars believed to trace the primordial abundance. Tweaking the theory of BBN to correct the lithium abundance affects that of the hydrogen or helium to an extent that this is ruled out by the Cosmic Microwave Background (CMB). In a very recent paper, Pasquale D. Serpico and Vivian Poulin (LAPTh, CNRS) have shown that a loophole in the calculation of the electromagnetic cascades re-opens the possibility of finding an easy way out to the old problem of the lithium abundance. A course on cosmology by Wessel ValkenburgStarting Monday 20 January Wessel Valkenburg (Lorentz Institute, Leiden Univ., NL) will give a series of 5 lectures on cosmology. The lectures require no prior knowledge of the subject and is addressed to both theorists and experimentalists, physics PhD students and researchers alike. The 5 lectures Introduction to Cosmology cover The (6) videos of the lectures can be found on the LAPTh Youtube Channel Habemus LogoA new logo is born !LAPTh has now a new logo! Putting 5 letters in a square was no easy job. Among a hundred of designs and a lot of discussions in the LAPTh patio, restaurant, sometimes heated but always jovial, this was the final choice. The logo comes now in a couple of versions.
New Planck results, another one bites the dustAfter four years of operation of the Planck satellite of the European Space Agency (ESA), the Planck Collaboration has build up an exquisitely precise map of the sky in both temperature and now of polarisation. These maps furnish a detailed picture of how the universe evolved. Among the numerous results provided by the Planck satellite over the last year, there is an assessment of the polarised dust emission at intermediate and high Galactic latitudes (http://arxiv.org/abs/1409.5738). This is a crucial foreground in the searches for primordial B-mode polarisation patterns, possibly imprinted in the Cosmic Microwave Background by gravitational waves of inflationary origin, also known as tensor modes. Thanks to this measurement, older estimates of this contribution have been revisited and, in a joint effort by the BICEP2/Keck Array and Planck Data collaborations (http://arxiv.org/abs/1502.00612), no statistically significant evidence for tensor modes has been found in a reanalysis of the BICEP 2 observations, which in 2014 had been interpreted as a possible primordial B-mode detection (http://arxiv.org/abs/1403.3985), an interpretation that made big waves in the media then... undeservedly. We will need to wait and be more careful about gravity waves. Plus d'articles... |
9 Chemin de Bellevue - BP 110 - Annecy-le-Vieux - F-74941 ANNECY Cedex - FRANCE, TEL : +33 (0)4 50 09 16 84
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