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 Jean-René Chazottes, 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 Partenariat Hubert Curien

The string group is organising a topical day with informal blackboard presentations and discussion.

Journée Partenariat  Hubert Curien

Asymptotic Symmetries, Conformal Field Theories and Applications to Quantum Hall Effect

December 2 2024 10:30 AM at CPHT, room Jean Lascoux.

10h30-12h30 : Rodrigo Olea (Santiago), Matthieu Vilatte (Mons), Marc Geiller (Lyon)

14h-17h : Jibril Ben Achour (Lyon-Munich), Mathieu Beauvillain (Palaiseau), Blagoje Oblak ( Lyon), Simon Pekar (Trieste), Anastasios Petkou (Thessalonique)

Poster

English

Séminaire général

Séminaire de Carlota Andres-Casas, 21/11/2024, 11h, au CPHT, Salle JEAN LASCOUX

Probing the Quark-Gluon Plasma with Energy Correlators

Recent advances in conformal field theory have led to the reformulation of collider jet substructure as the study of correlation functions of the energy flux, known as energy correlators, and their associated light-ray operator product expansion (OPE). Multi-point energy correlators have been measured in proton-proton collisions at the Large Hadron Collider (LHC), offering experimental validation of the light-ray OPE. In this talk, I will highlight the advantages of using energy correlators to probe the quark-gluon plasma produced in heavy-ion collisions, for which the first energy correlator measurement has recently been unveiled. Building on the unique properties of energy correlators, I will introduce a novel observable that stands as the first heavy-ion jet substructure observable where energy loss (or selection bias) is not the leading effect.

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Mathematical physics seminar

 

Mathematical physics seminar, on Monday november 18, 2024, 2 pm, in the lecture room Louis Michel at CPHT

Jürg Fröhlich (ETH Zürich)

"The stochastic evolution of isolated systems in quantum mechanics"

Abstract: In this talk I describe a Law of Dynamics for non-relativistic Quantum Mechanics (QM). The time evolution of physical systems consisting of charged matter interacting with the quantized electromagnetic field, e.g., electrons in the shell of an atom coupled to the radiation field, is non-linear, dissipative and stochastic, featuring isolated random events sometimes called “quantum jumps”. We discuss the equations describing it ! They involve a new type of stochastic process, dubbed “quantum Poisson jump process." An application to the phenomenon of fluorescence will be sketch

English

New trends in QFT, modularity and resurgence, on Wednesday November 6 at Institut Henri Poincaré

We are happy to launch a new thematic trimester on New trends in QFT, modularity and resurgence.
We will start with an in-person kick-off event on November 6, from 13:30 to 17:30, at Institut Henri Poincaré, Paris.

We are very excited about the contributions from our three speakers for this event:

Antoine Tilloy (LPENS, Mines Paris, Inria) - A variational approach to QFT in low dimensions?

Campbell Wheeler (IHES) - Matrix cocycles and Borel resummation

Claudia Rella (IHES) - The arithmetic of resurgent topological strings

To attend our kick-off event in person, there is a free but mandatory registration: https://seedseminar.apps.math.cnrs.fr/registration

We will also share a Zoom link via this mailing list for those of you who cannot make it in person.
After the kick-off event of November 6, the trimester will continue with our traditional online talks every two weeks, which will be delivered as hybrid events at the IHES (more info soon). Details will be announced via this list.
For further information: https://seedseminar.apps.math.cnrs.fr

Kind regards,
Matteo D’Achille, Aymane El Fardi, Veronica Fantini, Emmanuel Kammerer, Edoardo Lauria, Sophie Mutzel, Junchen Rong

Mailing list of the Seed Seminar of Mathematics and Physics More info at: https://seedseminar.apps.math.cnrs.fr/
 

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An article published in the journal Science

 

A new way to assess the progress of simulation techniques in quantum physics

In an article published in the journal Science, an international collaboration involving researchers from the Centre for Theoretical Physics (CPHT) proposes a tool for estimating the difficulty of many problems yet to be solved, as well as the effectiveness of methods developed to tackle them, including quantum algorithms.

Link to scientific publication: Variational benchmarks for quantum many-body problems, Science, 386, 6719, 2024. DOI: 10.1126/science.adg9774

Read the press release from Ecole polytechnique

English

CPHT Condensed Matter Seminar

 

Tuesday 08/10 at 14:30

at CPHT, Conference room Louis Michel

B. J. Kim (POSTECH, Republic of Korea)

Origin of chirality in the charge density wave semimetal 1T-TiSe2

Abstract: Chirality is a ubiquitous phenomenon in which a symmetry between left- and right-handed objects is broken, examples in nature ranging from subatomic particles and molecules to living organisms. However, mechanisms that lead to chirality in condensed matter systems remain poorly understood. In this talk, I will discuss on a novel mechanism of chiral charge density wave formation in the transition-metal dichalcogenide 1T-TiSe2. Based on a rigorous symmetry analysis, we show that charge density modulations and ionic displacements, which transform as a continuous scalar field and a vector field on a discrete lattice, respectively, follow different irreducible representations of the space group, despite the fact that they propagate with the same wave-vectors and are strongly coupled to each other. This charge-lattice symmetry frustration is resolved by further breaking of all symmetries not common to both sectors through induced lattice distortions, thus leading to chirality. Our theory is verified using Raman spectroscopy and inelastic x-ray scattering, which reveal that all but translation symmetries are broken at a level not resolved by state-of-the-art diffraction techniques.

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