Presentation of IPhT : The Institute of Theoretical Physics (IPhT) is an Institute of the Direction of Fundamental Research (DRF) of the Commissariat for Atomic Energy and Alternative Energies (CEA).

EPS PhD prize awarded to IPhT student

**The Nuclear Physics Division of the European Physical Society has awarded Giuliano Giacalone, a former student of IPhT, its PhD prize.**

This prize is awarded every third year, and the ceremony took place during the EuNPC 2022 conference in Santiago de Compostela, Spain, in October 2022.

https://indico.cern.ch/event/1104299/page/26561-npd-2021-phd-prize-winners

Giuliano, now a postdoc at the University of Heidelberg, completed his PhD thesis "Observing the shape of nuclei at high-energy colliders" in November 2020 under the supervision of Jean-Yves Ollitrault. His thesis has previously been honoured with an award of the French Physical Society.

https://www.sfpnet.fr/accessits-prix-jeunes-chercheurs-euses-2020-de-la-sfp

Congratulations!

E. De-laborderie, 2022-11-04 10:33:00

Exact results for the "box ball system", a cellular automaton with solitons

__ Figure caption:__ The rules governing the dynamics of the balls in the "box ball system" can be illustrated with the help of a carrier that loads and unloads the balls by running through the system from left to right at each time step.

Understanding how macroscopic laws and large-scale properties emerge from the microscopic interactions between the constituents of a system is a major problem in statistical physics. One can for instance consider the appearance of hydrodynamic behaviors or the way currents react to external forces. It is generally very challenging to connect the microscopic rules to these large-scale properties, and there are relatively few systems for which exact results can be obtained.

The “Box-ball system” (BBS), a particular cellular automaton, is such an example. The BBS consists of “balls” occupying “boxes” arranged on a line, with at most one ball per box. Although the balls move at each time step according to simple deterministic rules (see figure/animation), the BBS presents a rich physics due to the fact that we can identify some objects called "solitons" (a train of k consecutive balls) of all size and whose number are preserved over time.

Using the integrability of the model a recent study of **G. Misguich and V. Pasquier, researchers at the IPhT, together with A. Kuniba (Tokyo U.) [1] ** has shown how to determine several quantities related to currents and their fluctuations. These include the probability distribution of the number of balls passing through the origin during a time t, the long-time persistent current generated by a perturbation -- called Drude weight --, and some correlation functions associated with soliton currents.

[1] “Current correlations, Drude weights and large deviations in a box–ball system”, A. Kuniba, G. Misguich and V. Pasquier, J. Phys. A: Math. Theor., 55 244006 (2022). (https://doi.org/10.1088/1751-8121/ac6d8c) See also J. Phys. A: Math. Theor. 53 404001 (2020). (https://doi.org/10.1088/1751-8121/abadb9)

E. De-laborderie, 2022-10-11 10:10:00

Exact Macroscopic Fluctuations Far from Equilibrium

Many natural systems remain far from thermodynamic equilibrium by exchanging matter, energy or information with their surroundings. As these transfers, or fluxes, break timereversal invariance, such processes are beyond the realm of traditional thermodynamics and their statistical fluctuations do not follow the principles of equilibrium statistical mechanics.

Though a fully general theory of non-equilibrium systems still remains to be constructed, a physical principle describing the macroscopic behaviour of diffusive systems far from equilibrium has been proposed by G. Jona-Lasinio and his collaborators in 2001: this is the Macroscopic Fluctuation Theory (MFT). In the MFT framework, macroscopic fluctuations far from equilibrium are determined by two coupled non-linear hydrodynamic equations. However, for a long time, the MFT equations have remained intractable.

In a recent work that has appeared in *Physical Review Letters, K. Mallick (IPhT), H. Moriya and T. Sasamoto (Tokyo Tech.)* have discovered an exact analytic solution for the time-dependent MFT equations for the symmetric exclusion process, a paradigmatic model of non-equilibrium statistical physics. The MFT was solved by using Inverse Scattering Theory, originally invented to study dispersive waves such as solitons in hydrodynamics or in optical guides. This classic method of non-linear physics is strikingly relevant to establish exact results in non-equilibrium thermodynamics and allows us to predict quantitatively the appearance of rare events and dynamical fluctuations. The application of soliton theory to non-equilibrium statistical mechanics might have far reaching consequences.

E. De-laborderie, 2022-08-25 15:09:00

Preparation of the exploitation of the Euclid mission

2022-07-11 16:06:00

Retreat of the IPhT in Autrans : aftermath

2022-06-22 09:05:00

Arrival of Ben Wieder on next september

2022-06-17 15:12:00

Arrival of Dalimil Mazáč at IPhT

2022-06-07 10:14:00

Maps day at IPhT on 24 June 2022

2022-06-03 10:33:00

Quantum bounds and fluctuation-dissipation relations

2022-05-12 11:47:00

26ème conférence Itzykson : "Black-Hole Microstructure IV"

2022-05-12 10:32:00

Colloquium Rencontres de l'IPhT in Autrans (Vercors) from 23 to 25 May.

2022-05-12 10:02:00

An extension of Tutte's formula 60 years later

2022-04-20 11:13:00

2022-04-05 11:28:00

Public talk of Stephane Lavignac on Tuesday March 15th

2022-03-11 09:17:00

A new book written by Marc Barthélémy about spatial networks

2022-02-22 11:05:00

Cédric Villani at IPhT on March 1st

2022-02-22 10:26:00

Summer School in Cargèse around exotic superconductivity

2022-02-07 15:39:00

Langevin Prize of the French Society of Physics for Mariana Graña

2022-02-04 10:46:00

2022-02-01 09:59:00

2022-02-01 09:21:00

Maxime Leroy joins the IPHT support team

2022-01-27 15:24:00

Un lien entre la masse du boson de Higgs et la constante cosmologique

2021-11-25 14:11:00

Conférence exceptionnelle de Cédric Villani le lundi 22 novembre à 19h30 (Institut Pascal)

2021-11-18 14:33:00

Problems in Quantum Field Theory : a book by François Gelis.

2021-10-11 16:12:00

Mathematical Harmony and the Quantum World

2021-10-07 15:24:00

The art of mathematical physics

2021-09-01 16:31:00

Correlation functions and wave functions in solvable models

2021-08-31 16:44:00

2021-05-01 11:45:00

Multipole Ratios : A New Window into Black Holes

2020-11-27 15:16:00

Orazio Scarlatella lauréat du prix de thèse Physique des Ondes et de la Matière (PhOM) 2020

2020-11-26 11:07:00

Modeling the city: an equation ends centuries-old controversies

2020-11-19 11:10:00

Quantum entanglement: A single photon takes two optical paths by "entangling" them!

2020-10-15 15:06:00

An strongly secured encryption

2020-09-17 17:01:00

David Kosower lauréat de l'ERC Advanced Grant "Ampl2Einstein"

2020-04-03 15:57:00

Un nouvel ouvrage co-écrit par Pierfrancesco Urbani, physicien à l’IPhT

2020-01-31 14:15:00

Un nouvel ouvrage co-écrit par Henri Orland, physicien à l'IPhT

2020-01-28 16:16:00

Mon, Feb. 06th, 11:00-12:00

Séminaire de physique mathématique - Sylvain Ribault

Thu, Feb. 09th, 14:00-15:00

Séminaire de physique des particules et de cosmologie - Deog Ki Hong