The center for Theoretical Physics (CPHT) at Ecole Polytechnique gathers research scientists working in diverse domains of fundamental and applied Physics. The overall coherence is assured by the corpus of common, transposable, mathematical and numerical methods.
CPHT is a joint research unit of CNRS and Ecole Polytechnique, and has a partnership with the Collège de France. His director is Marios Petropoulos, Senior Researcher at CNRS.
CPHT is on the campus of Ecole Polytechnique, buildings 5 and 6. The reception offices are located in building 6 , offices 06.1046 and 06.1045.
 

Postal Address :
CPHT 
Ecole Polytechnique 
91128 Palaiseau cedex 
France

Secretary phone number : 01 69 33 42 01 (from abroad: +33 169 334 201)

Write an email to someone at CPHT :  : firstname.lastname@polytechnique.edu

 

Journée scientifique CMLS-CPHT et débat théâtral – 16 mars 2026

Le CMLS et le CPHT ont le plaisir de vous inviter à une journée scientifique un peu particulière qui se tiendra le lundi 16 mars 2026.
 
Au programme de cette journée :
 
- Le matin, de 10h à 12h, deux exposés de type colloquium dans la salle Jean Lascoux (CPHT, rez-de-chaussée de l’aile 0) :
 
 - Maria Chatzieleftheriou (CPHT)
 - Enrica Mazzon (CMLS).
 
- Déjeuner (buffet)
 
- À partir de 13h30  : représentation de la pièce "Entre les lignes” par la compagnie « Entrée de jeu », en amphi Poincaré.
 
- Après la représentation, goûter avec les comédiens.
 
Cette journée sera l'occasion de croiser les regards entre mathématiques et physique théorique, et d'interroger collectivement, à travers un débat théâtral, les enjeux d'égalité et d'inclusion dans la recherche.
Les détails pratiques (horaires, lieu exact, résumés des exposés) vous seront communiqués dans les prochaines semaines.
Nous espérons vous y voir nombreuses et nombreux !
 
Bien cordialement,
Jean-René Chazottes (CPHT), Lorenzo Fantini et Pascale Harinck (CMLS)
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Podcast sur France culture : La gravitation quantique selon le principe holographique

Marios Petropoulos et Adrien Fiorucci ont participé à un podcast consacré à Sabrina Pasterski (Perimeter Institute) pour Radio France. Ils y parlent de leurs recherches au CPHT sur la formulation d'une correspondance holographique en espace-temps plat au moyen de méthodes de physique non-relativiste.

Le podcast sera diffusé le Jeudi 12 mars 2026.

Lien : Podcast

 

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Seminar at CPHT

 
Date:        Mercredi 11 Mars 2026
Heure: 11:00
Salle: Salle de Conférence Louis Michel
Speaker: Wenqi Ke (Minnesota University)
Title: From spin-3/2 to supergravity: an on-shell reconstruction
 
Abstract: The spin-3/2 field (the gravitino) arises as a consequence of local supersymmetry and appears as the superpartner of the graviton. This raises the converse question: can a consistent spin-3/2 theory lead to supersymmetry, and in turn require the presence of a graviton? Work from the 70s answered this in the affirmative for massless spin-3/2. In this talk, I will address the massive spin-3/2 case using the on-shell formalism, and show that interactions characteristic of spontaneously broken supergravity emerge naturally from consistency conditions such as Lorentz invariance and unitarity.
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Seminar at CPHT

Date: Mardi 10 Mars 2026
Heure: 11:00
Salle: Salle de Conférence Louis Michel
 
Spearker: Nelson Merino Moncada (Universidad Arturo Prat)
Title: The Katz, Bicák and Lynden-Bell (KBL) regularization and its applications
 
Abstract: The Katz boundary term provides a well-defined variational principle under Dirichlet boundary conditions and, when combined with a subtraction of the action evaluated on a background, known as the KBL regularization procedure, yields finite Noether charges and a finite on-shell action. This boundary term is constructed from the dynamical metric and the difference between the Christoffel symbols associated with the dynamical manifold and a reference background. So far, this method has been tested only for specific solutions. In this work (soon to be submitted for publication), using the Fefferman-Graham gauge, we show that the finiteness of conserved charges can be proven for families of asymptotically locally Anti–de Sitter spacetimes in general relativity. The finiteness of the charges can be established in arbitrary dimensions; however, the prescription for defining the background in this framework distinguishes between even and odd spacetime dimensions. Other possible applications and potential relations with the covariant phase space method will also be discussed.
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Deux doctorants du CPHT et un étudiant de l'INSA Centre Val de Loire remportent le Hackathon Mistral AI Paris 2026

Toutes nos félicitations à Emma Grospellier et Godefroy Meynard, tous deux en thèse au Centre de Physique Théorique (CPHT) de l'École polytechnique, ainsi qu'à Esteban Soubiran diplomé de l'INSA Centre Val de Loire.

Ils ont décroché la première place de l'édition 2026 du Hackathon Mistral AI avec leur projet Veristral !

Développé en un temps record lors de la compétition, Veristral est un outil novateur propulsé par les modèles de Mistral AI. Il permet d'effectuer du "fact-checking" d'affirmations politiques en temps réel, alliant exigence scientifique, rapidité d'exécution et impact sociétal direct.

Un immense bravo à Emma et Godefroy pour cette brillante victoire qui démontre, une fois de plus, la capacité de nos chercheurs à transformer la complexité technique en solutions concrètes. 

hashtag#MistralAI hashtag#Hackathon2026 hashtag#EcolePolytechnique hashtag#CPHT hashtag#Veristral hashtag#FactChecking hashtag#Innovation hashtag#IA

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Ma thèse en 180 secondes

Bravo à Magali qui a été qualifiée pour la finale régionale.

Magali Korolev qualifiée pour la finale IP Paris – Ma thèse en 180 secondes.

La finale IP Paris se tiendra le :

Mercredi 12 mars à 10h00
Amphi Poincaré

Lors de cette finale, elle présentera ses travaux de thèse en 180 secondes, aux côtés de neuf autres finalistes.

N’hésitez pas à venir assister aux discours et l’encourager !

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Seminar at CPHT February 27th Friday

Speaker: Emma Bonvarlet (Bachelor)

Time: 11:00 am, February 27th Friday 

Location: Salle de Conférence Jean Lascoux

 

Title: A precision tradeoff: balancing entanglement and variance in noisy quantum simulations

 

Classical simulation of quantum computation faces an immediate storage problem: a system of n qubits requires 2^n complex numbers to describe, an amount that grows exponentially beyond the reach of a modern supercomputer. To address this issue, we utilize tensor network representations (MPS) coupled with quantum trajectories to efficiently represent our state. These trajectories describe stochastic numerical evolutions that replace a single, massive density matrix with an ensemble of individual "paths".
 
However, this computational efficiency comes at a statistical price. Indeed, efficient MPS representation requires low entanglement, so we tend to try and minimize it. By doing so during each trajectory, we observed empirically that the statistical variance of the measured observable explodes. We then have cheaper individual simulations, but the need for a larger ensemble of trajectories to have a trustworthy physical measure. How can we characterize and understand this tradeoff?
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Seminar at CPHT Feb 25th Wednesday

Speaker: Antoine Rignon-Bret

Time: 14:00 pm, Feb 25th Wednesday  

Location: Salle de Conférence Louis Michel

 

Title:  The second law: from Lindblad equation to black holes

 

Abstract: In this talk, I will present how techniques from quantum information theory and quantum thermodynamics can be used to derive the second law of thermodynamics for quantum fields. I will begin with the case of a finite quantum system undergoing a Markovian evolution driven by an infinite bath, whose dynamics are governed by the Lindblad equation and whose thermodynamic properties are well understood. Building on this framework, I will show how a natural generalization allows us to extend these methods to the thermodynamics of quantum fields defined on causal horizons. Unlike finite quantum systems, quantum field theory admits many unitarily inequivalent Hilbert spaces, each constructed from a distinct choice of vacuum state. I will argue that these different vacua can be interpreted as corresponding to different reservoirs driving the dynamics. In particular, I will demonstrate how Wall’s proof of the generalized second law fits naturally within this framework, and how analogous thermodynamic laws describing black hole thermodynamics emerge for asymptotic observers. These laws correspond to different thermodynamic potentials associated with distinct vacuum states, such as the Boulware, Hartle–Hawking, and Unruh vacua.

 

Zoom Link: https://ecolepolytechnique.zoom.us/j/97688194627?pwd=5byaoDaJ9J0kubMRXYKA09xWHfwxUK.1

 

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Seminar at CPHT Feb 18th Wednesday

Speaker: Michal P. Heller

Time: 14:00 pm, Feb 18th Wednesday  

Location: Salle Jean Lascoux

 

Title:  Quasinormal perspective on nonthermal fixed points

 

Abstract: I will present nonthermal fixed points as paradigmatic far from equilibrium weak coupling phenomena characterised by a self-similar evolution in time. I will then discuss what strong coupling perspective based on the quasinormal modes insights into holographic thermalization and hydrodynamics can teach us about nonthermal fixed points. Based on 2307.07545, 2502.01622 and 2504.18754.

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Seminar at CPHT

Speaker: Mitchell Woolley

Time: 16:00 pm, Feb 2th Wednesday  

Location: Salle de Conférence Louis Michel

 

Title:  The W-algebra bootstrap of 6d (2,0) theories (Continued.....)

 

Abstract: We outline progress toward the superconformal bootstrap of the mixed correlator bootstrap of 6d (2,0) SCFTs. The first step was achieved in [2506.08094], where we used the conjectured cohomological reduction of 6d (2,0) SCFTs to W-algebras to extract an infinite set of protected mixed correlator CFT data. To that end, we explicitly construct the W_g algebras of 6d (2,0) theories of type g={A,D} and impose Jacobi identities on generator OPEs to fix CFT data. We uplift this data and the twisted correlators to 6d and show how our CFT data is organized along conformal Regge trajectories. As an application, we demonstrate the consistency of this information with protected higher derivative corrections in the M-theory holographic dual on AdS_7 x S^4/Z_o.

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