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).
Teaching ideal quantum measurements  
A new article by Roger Balian, Armen Allahverdyan, and Theo M. Nieuwenhuizen!


Former director of the Service de Physique Théorique de Saclay (1979-1987) [1], our friend and colleague Roger Balian has just published with his collaborators Armen Allahverdyan, Yerevan Physics Institute, and Theo M. Nieuwenhuizen, Institute for Theoretical Physics Amsterdam, on the journal Comptes Rendus. Physique de l'Académie des Sciences [2].

In this publication, the authors present a graduate course on ideal measurements, which are dynamic processes coupling the quantum system under test and a measuring device, analyzed within the framework of quantum statistical mechanics.

[1] Short biography in « Roger Balian is 80! »

[2] Comptes Rendus. Physique 2024, Vol. 25, p. 251-287.

R. Guida, 2024-07-12 20:18:00


Next arrival of Olivier Gingras at IPhT!  
Olivier Gingras will join the IPhT in early 2025 on a permanent joint position at the IPhT and the QCC, Flatiron, New York. Part of the challenge of this position will be to facilitate interactions and collaborations between the two institutes on the theme of the quantum N-body problem.


Olivier did his PhD in Sherbrooke and Montreal, Canada, on the N-body quantum problem, and acquired expertise in DFT (Density Functional Theory), DMFT (Dynamical Mean Field Theory) and the physics of superconducting gap symmetry in Strontium Ruthenate compounds. Since 2022, he has been a post-doc at CCQ, during which he has been able to broaden his numerical expertise without forgetting interactions with experimentalists.

With his openness to a wide range of numerical expertise and his sensitivity to the importance of experimental studies in quantum materials research, Olivier will be a tremendous asset to numerical and phenomenological physics on the Saclay plateau, and will be essential in federating and maintaining collaboration between DRF and CCQ. Welcome to the IPhT Olivier, for a brilliant career ahead!

E. De-laborderie, 2024-07-05 14:19:00


Supersymmetry Meets Random Matrices  
Gregory Korchemsky, Zoltan Bajnok and Bercel Bordis have recently developed a new general method for systematically calculating a class of observables in strongly coupled four-dimensional supersymmetric gauge theories.


Computing observables in quantum field theory in the regime when the particles interact strongly represents a fundamental challenge in theoretical physics. Supersymmetric quantum field theories, which are characterised by interactions that preserve a symmetry relating bosons (integer spin) and fermions (half-integer spin), offer a powerful training ground for developing the computational tools that are required to address this problem.

A team consisting of Gregory Korchemsky (Institut de Physique Théorique, CNRS) and two Hungarian collaborators, Zoltan Bajnok and Bercel Bordis (HUN-REN Wigner Research Center for Physics),  has recently developed a new, general method to systematically compute a special class of important observables in strongly coupled four-dimensional supersymmetric gauge theories. Their findings has recently been published in the prestigious journal Physics Review Letters as Editors' Suggestion [1].

A distinguished feature of these observables is that, in the limit of a large gauge group rank (planar limit) and for any 't Hooft coupling, they can be expressed as determinants of certain semi-infinite matrices. Crucially, the same determinants have previously appeared in the context of random matrix theory, where they were computed exactly in terms of a well-known probability distribution known as the "Tracy-Widom distribution" (or a more general version of it).

This distribution is a powerful tool for analyzing a wide range of complex systems in physics (quantum chaos, directed polymers, surface growth, turbulence, etc.), revealing the underlying connections between seemingly disparate physical phenomena.

The Tracy-Widom distribution proves surprisingly versatile in supersymmetric gauge theories. It describes observables like the free energy on a sphere and correlations of specific operators and even more applications are anticipated. The team's findings provide a systematic treatment and new insights into the strong coupling regime of four-dimensional supersymmetric gauge theories, inviting further investigations in related theoretical frameworks. The technique developed by the authors is quite general and can be applied to determine the asymptotic behavior of a general class of determinants involving the so-called "Bessel operators", this opening a new avenue for many physical and mathematical applications.

[1] Zoltan Bajnok, Bercel Boldis, and Gregory P. Korchemsky. Tracy-Widom distribution in four- dimensional supersymmetric Yang-Mills theories. Phys. Rev. Lett. 133, 031601.

R. Guida, 2024-07-04 15:21:00


SLE multifractal news

2022-04-05 11:28:00

Arrival of Pierre Fleury

2022-02-01 09:21:00

An strongly secured encryption

2020-09-17 17:01:00

François David
Presentation of IPhT
Catherine Pépin
What is so facinating about supraconductivity?
David Kosower
Precision Calculations in the Search for Unification


Retour en haut