A course on Nonequilibrium Processes

Kirone 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.
2. Out of Equilibrium: Large Deviations, Generalized Detailed Balance and the Gallavotti-Cohen theorem.
3. Work Identities: the Jarzynski and Crooks identities.
4. The Asymmetric Exclusion Process: Exact Results
5. A unifying framework: the Macroscopic Fluctuation Theory.

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.

Lire la suite : A Possible solution to the Lithium problem?

A course on cosmology by Wessel Valkenburg

Starting 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
 
1) The universe today: overview of current understanding, based on Planck, WMAP, SDSS, an many more.
2) Cosmic microwave background as the Planck satellite sees it: from radio signals to spectra of perturbations (and back), and the importance of spectra.
3)  Large scale structure from BOSS, CFHTLens, LSST, Euclid: from angles and redshifts to spectra of perturbations (and back), and a bit on the importance of spectra.
4)  Inflation: probing high-energy physics with BICEP2, Planck, and others.
5) What are the most important pitfalls for cosmologists? Confirmation bias, believe vs pragmatic testing, etc. Where is the Nobel prize hiding?
 
For more information see the LAPTh indico : https://indico.in2p3.fr/category/365/

The  (6) videos of the lectures can be found on the LAPTh Youtube Channel

Habemus Logo

A 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.