The CPHT Young Researchers Seminar will be held on Monday the 30th of June at 3:00 PM  in room Louis Michel :

Valentine Maris from ENS de Lyon Introduction to noncommutative geometry and deformed Minkowski space-time :
Noncommutative geometry provides a representation of space-time in terms of associative algebras of operators. The final goal is to end up with a "quantum space-time" which should encode quantum gravity effects at an effective level. Recently, construction of such quantum space-times has been investigated and led to deformations of the usual Minkowski space-time.

Thomas Pochart QFT in AdS and its flat-space limit :
The Anti-de Sitter space is a fundamental concept in physics, arising naturally in GR and playing a key role in holography. We will discuss recent advances in quantum field theory for AdS spaces, and in particular its large radius limit, in which it is expected that we efficiently recover flat-space quantities.

The seminar will be followed by a high tea.

The CPHT Young Researchers Seminar will be held on Friday the 13th of June at 2:00 PM  in room Louis Michel :

Fanny Eustachon  CFT in higher dimensions for dummies

Francesco Cassol Interplay of Spin-orbit coupling, Coulomb interaction and magnetism in iridate materials: the example of Ba2IrO4 and Sr2IrO4

The seminar will be followed by a high tea.

L'IPP a reçu 68 candidatures pour le prix IP Paris de la meilleure thèse 2025, dont beaucoup étaient d'une qualité exceptionnelle. Après une longue et difficile délibération, le comité des prix de thèse a décidé d'attribuer 2 prix de la meilleure thèse de l'IP Paris (ex-aequo) et 7 prix de la meilleure thèse de doctorat du département.

Parmi eux, Matthieu Vilatte a reçu le prix de la meilleure thèse de doctorat du département de physique pour son travail intitulé : "Adventures in (thermal) Wonderland : Aspects of Carrollian physics, asymptotically flat spacetimes and thermal field theory ». Cette thèse a été encadrée conjointement par Tasos Petkou (Université Aristote de Thessalonique, Grèce) et Marios Petropoulos (Centre de Physique Théorique, École polytechnique).

Les résultats seront officiellement annoncés

Quantum, highlighted in this year 2025, is one of the major research field at the Center for Theoretical Physics. The researchers of the laboratory develop a variety of activities around quantum materials, quantum simulation, quantum computing, and quantum machine learning, among others. An overview of this 'second quantum revolution' with Laurent Sanchez-Palencia, head of the Quantum Matter team at CPHT, in an article published on the École Polytechnique website.

Une étude publiée dans The Astrophysical Journal Letters par une équipe internationale* coordonnée par Tahar Amari, directeur de recherche CNRS au Centre de physique théorique de l’École polytechnique (CPHT**), démontre que des structures appelées cordes magnétiques sont omniprésentes dans le Soleil, y compris dans ses régions les plus calmes. Leurs travaux, mêlant observations à haute résolution et simulations avancées, expliquent comment ces cordes participent à chauffer l’atmosphère solaire à des températures extrêmes.

Communiqué de presse de l'Ecole polytechnique

Communiqué de presse de CNRS Physique

The Seed seminar of mathematics and physics is a seminar series that aims to foster interactions between mathematicians and theoretical physicists, especially among young researchers. It is structured into three-month thematic periods.

We organize an in-person workshop at the Institut Pascal resuming the trimesters of this academic year with contributions from Nicolas Curien, Boris Pioline, Clément Delcamp, Balt van Rees and Stavros Garoufalidis.

Organizers: Matteo D’Achille, Aymane El Fardi, Veronica Fantini, Emmanuel Kammerer, Edoardo, Sophie Mutzel, Junchen Rong

More information : https://indico.ijclab.in2p3.fr/event/11715/overview

Poster

We are pleased to announce that the next "Biséminaire Friedmann CPHT-LLR" will be held on May 6, 2025 at the CPHT (Ecole Polytechnique), Salle Louis Michel.

11:00 - Sébastien RENAUX-PETEL (Institut d'Astrophysique de Paris)

New Particles in the Sky
Inflation literally acts as a cosmological collider: it spontaneously produces all types of particles, which leaves peculiar imprints in the correlation functions of primordial density fluctuations. Primordial correlators thus hold the key to high-energy physics inaccessible by other means. However, they are much harder to compute than flat space amplitudes. In this talk, I will describe these opportunities and challenges, as well as analytical and numerical techniques that have been developed in the past few years to better understand quantum field theory in curved spacetime.

14:30 - Vincent VENIN (Laboratoire de Physique, ENS Paris)

Quantum diffusion and primordial black holes in the early universe
When primordial inhomogeneities are produced with sufficiently large amplitude in the early universe, they may subsequently collapse into primordial black holes. I will explain why the effect of quantum diffusion during inflation needs to be taken into account in such a case, and how the statistics of cosmological fluctuations can be predicted within the formalism of stochastic inflation. Quantum diffusion leads to a peculiar type of non-Gaussianity that cannot be captured by perturbative parametrisations. This leaves specific imprints on the statistics of collapsed structures that I will discuss. In particular, I will present recent results on the clustering of primordial black holes, which conditions the rate at which they merge and emit gravitational waves.

Lien zoom : https://ecolepolytechnique.zoom.us/j/7410042935

Comité Friedmann: S. Biermann, J.-R. Chazottes, M. de Naurois, P. M. Petropoulos, Y. Sirois

Organised in cooperation with the Fondation de l'X, the Fonds Alexandre Friedmann and the Laboratoire Leprince-Ringuet (Ecole polytechnique).

Cours Thématiques du CPHT

Title: An Introduction to Conformal Field Theory in 2 + 1 Dimensions

Two lectures by Junchen RONG (CPHT)

Centre de Physique Théorique, École polytechnique
Salle de conférences Louis Michel
April 7 & 11, 2025 from 11:00 to 13:00

Abstract:
In this series of lectures, I will explore conformal field theories (CFTs) in 2 + 1 dimensions and the renormalisation group flows connecting them. I will begin by examining scalar CFTs, which correspond to Wilson-Fisher fixed points in 4− ε dimensions, focusing on their stability properties from a modern perspective. Following this, I will discuss 2 + 1 dimensional gauge theories with bosonic or fermionic matter. If time permits, I will also discuss the connections between these CFTs and quantum/statistical phase transitions.

Lien zoom : https://ecolepolytechnique.zoom.us/j/7410042935

Organisers: Adrien FIORUCCI, Marios PETROPOULOS, Mikel SANCHEZ

The Collège de France Condensed Matter Physics Chair's cycle of lecturesand seminars begins on Wednesday April 30, and this year's topic is:

“Cold fermions and quantum simulation”.

Courses are in French and seminars in English.
The courses can be validated as part of the doctoral training program: register here.

Organized by: Antoine Georges (Professor, Collège de France)

Further information : here

Poster