École Normale Supérieure Summer Institute 2024

20 juin 2024, 09:00 → 28 juin 2024, 17:00 Europe/Paris

ENS and Collège de France

Boris Pioline (LPTHE, Sorbonne Université et CNRS), Bruno Le Floch (CNRS), Elias Kiritsis (UoC and APC), Francesco Nitti (APC, Université de Paris), Giuseppe Policastro (LPTENS), Kallia Petraki (ENS and Sorbonne University), Marc Henneaux (Université Libre de Bruxelles & Collège de France), Miguel Fernandes Paulos (Ecole Normale Superieure), Raffaele DAgnolo

We are looking forward to welcoming you to the 2024 edition of the ENS Summer Institute. The ENS Summer Institute aims to cover a broad spectrum of topics in high-energy physics and cosmology, and provide ample opportunities for discussion. 

This year, it will include topics on quantum gravity, holography and quantum field theory, while the phenomenological session will be devoted to axions. 

Special event: On Wednesday 26/06, we will celebrate the distinguished career and scientific legacy of our esteemed colleague, Costas Bachas, on the occasion of his retirement.

The meeting will be held at two different locations:

• 20-21 June at Collège de France, as part of the Colloque "Topics in Quantum Gravity"
• 22-28 June at École Normale Supérieure.
   

Recent past editions: 2023, 2018, 2017. 

Poster.pdf

jeudi 20 juin

10:30 → 11:00 Welcome coffee

11:00 → 12:00 Formal theory

11:00 No global symmetries and string universality

Orateur: Prof. Miguel Montero

14:00 → 15:00 Formal theory

14:00 Lower-dimensional gravity, DSSYK and group theory

In this talk, I will report on recent process in understanding lower-dimensional gravitational models structurally from group theory. The main strength of this approach seems to be its universality in describing different models. In particular, I will discuss how it can be used to argue for a bulk holographic dual of double-scaled SYK (DSSYK) in terms of sine dilaton gravity.

Orateur: Thomas Mertens (University of Ghent, Belgium)

15:00 → 15:30 Coffee Break

15:30 → 16:30 Formal theory

15:30 The Parisi-Sourlas Uplift and Infinitely Many Solvable 4d CFTs

Parisi-Sourlas (PS) supersymmetry is known to emerge in some models with random field type of disorder. When PS SUSY is present the d-dimensional theory allows for a d−2-dimensional description. In this paper we investigate the reversed question and we provide new indications that any given CFT_{d−2} can be uplifted to a PS SUSY CFT_d. We show that any scalar four-point function of a CFT_{d−2} is mapped to a set of 43 four-point functions of the uplifted CFTd which are related to each other by SUSY and satisfy all necessary bootstrap axioms. As a byproduct we find 43 non trivial relations between conformal blocks across dimensions.
We test the uplift in generalized free field theory (GFF) and find that PS SUSY is a powerful tool to bootstrap an infinite class of previously unknown GFF observables. Some of this power is shown to persist in perturbation theory around GFF.
We explain why all diagonal minimal models admit an uplift and we show exact results for correlators and CFT data of the 4d uplift of the Ising model. Despite being strongly coupled 4d CFTs, the uplifted minimal models contain infinitely many conserved currents and are expected to be integrable.

Orateur: Emilio Trevisani (CNRS - Sorbonne Université)

Uplift Ens Summer Institute 19_06_2024 copy.pdf

vendredi 21 juin

11:00 → 11:30 Coffee Break

11:30 → 12:30 Formal theory

11:30 Arithmetic Chaos Inside Black Holes

It has been known for over 50 years that spacetime dynamics becomes chaotic in the approach to singularities. Furthermore, the classical gravitational dynamics exhibits remarkable number-theoretic properties known as arithmetic chaos. I will review these facts and give an explicit realisation of these phenomena in the interior of an asymptotically AdS black hole. I will discuss possible implications for the nature of black hole singularities and black hole thermodynamics.

Orateur: Sean Hartnoll (University of Cambridge)

Paris 24.pdf

14:30 → 15:30 Formal theory

14:30 Tracking celestial and Carrollian theories

In this talk, I will present recent developments towards formulating a holographic correspondence for asymptotically flat spacetimes. In particular, I will discuss the role of newly uncovered symmetries in the so-called celestial and Carrollian holographic proposals.

Orateur: Laura Donnay (SISSA)

ENS_CollegedeFrance_Carroll&Celestial.pdf

15:30 → 16:00 Coffee Break

samedi 22 juin

10:30 → 11:00 Coffee Break

11:00 → 12:00 Formal theory

Président de session: Miguel Fernandes Paulos (Ecole Normale Superieure)

11:00 Nonrelativistic conformal field theory

We will review the notions of Schrödinger symmetry and nonrelativistic conformal field theory, in particular the restrictions that Schrödinger symmetry imposes on correlation function and the operator-state correspondence. We will then consider the most important example of NRCFT --- fermions at unitarity, and derive physical consequences of the formalism.

Orateur: Prof. Dam Son

lundi 24 juin

10:30 → 11:00 Coffee Break

11:00 → 12:00 Formal theory

Président de session: Miguel Fernandes Paulos (Ecole Normale Superieure)

11:00 The dual of semi-classical gravity

Recent work has produced a consistent picture of the holographic dual description of semi-classical gravity. I will describe this picture, several applications of this picture including the factorization puzzle and the information paradox, and some open questions.

Orateur: Prof. Jan de Boer

14:00 → 15:00 Formal theory

Président de session: Miguel Fernandes Paulos (Ecole Normale Superieure)

14:00 Energy Reflection and Transmission at 2D Holographic Interfaces

Scattering from conformal interfaces in two dimensions is universal in that the flux of reflected and transmitted energy does not depend on the details of the initial state. In this talk, I will present two gravitational calculations of the energy reflection and transmission coefficients for interfaces with holographic duals. I will first consider a thin-brane holographic toy model which is often used in the context of entanglement islands and black hole evaporation. I will demonstrate that the result for the reflection coefficient there depends monotonically on the tension of the brane. I will then extend the calculation to smooth domain-walls in 3-dimensional gravity. As an application, I will compute the transmission coefficient of a Janus interface in terms of its deformation parameter. I will demonstrate that both results obey bounds derived from the ANEC in conformal field theory.

Orateur: Prof. Shira Chapman

ENSSlidesChapman.pdf

15:00 → 15:30 Coffee Break

mardi 25 juin

10:30 → 11:00 Coffee Break

11:00 → 12:00 Formal theory

Président de session: Miguel Fernandes Paulos (Ecole Normale Superieure)

11:00 The entropy of Holographic CFTs at large charge and angular momentum

Black holes in AdS$_d$ (with $d\ geq 4$) are always unstable at large angular momentum, and sometimes unstable at large charge. In this talk we present proposals for the end point of these instabilities. Our constructions suggest new entropy formulae for ${\cal N}=4$ Yang-MIlls in the neighbourhood of extremality, and and in particular on the BPS manifold.

Orateur: Prof. Shiraz Minwalla

14:00 → 15:00 Formal theory

14:00 Toward stringy horizons

Orateur: Prof. Hong Liu

15:00 → 15:30 Coffee Break

mercredi 26 juin

09:00 → 10:15 Costas Bachas day

09:00 AdS3/CFT2 @ free point and beyond

Orateur: Matthias Gaberdiel (ETH Zurich)

Gaberdiel.pdf

09:25 Costas Bachas: (personal) strings

Orateur: Dieter Luest (Max-Planck-Institut fuer Physik, Ludwig-Maximilians-Universitaet)

09:50 Two Tales about 2d CFTs

Orateur: Hirosi Ooguri

Ooguri.pdf

10:15 → 10:45 Coffee Break

10:45 → 12:25 Costas Bachas day

10:45 Novel Modular Forms Arising in Correlators in N=4 SYM

Orateur: Michael Green

Green.pdf

11:10 Defects in fully extended TQFT -- A tour in pictures

Orateur: Ilka Brunner

Brunner.pdf

11:35 Interpolating between QFT and machine learning

Costas Bachas and I wrote several papers together on conformal field theory
and Dirichlet branes. In this talk I will try to connect these topics with my more recent
interests in machine learning.

Orateur: Michael Douglas

Douglas.pdf

12:00 BH and fuzzball perturbations from a gauge theory perspective

Orateur: Massimo Bianchi

14:00 → 15:15 Costas Bachas day

14:00 Magnetic charges in gravity

Orateur: Chris Hull

Hull.pdf

14:25 Back to D-Branes & Black Hole Information

Orateur: Erik Verlinde

14:50 From AdS_3 to Carroll fever and flat mania

Orateur: Marios Petropoulos

Petropoulos.pdf

15:15 → 15:45 Coffee Break

15:45 → 17:25 Costas Bachas day

15:45 The omnipresence of the Arrow of Time

Orateur: Vasilis Papadopoulos

Papadopoulos.pdf

16:10 Exponential S-matrix for Classical Observables

Orateur: Pierre Vanhove (IPhT CEA-Saclay)

Vanhove.pdf

16:35 Physics with Costas: exploring the String Landscape

Orateur: Igniatios Antoniadis (Ecole Polytechnique Centre de Physique Theorique (CPHT))

Antoniadis.pdf

17:00 Supersymmetry Breaking Cascade Flow from N=2 to adjoint QCD

Orateur: Eric D'Hoker

D'Hoker.pdf

jeudi 27 juin

10:30 → 12:00 Phenomenology

Président de session: Kallia Petraki (ENS and Sorbonne University)

10:30 Coffee break

11:00 A Holographic View of the QCD Axion

Orateur: Tony Gherghetta (University of Minnesota)

Gherghetta - HolographicAxion.pdf

14:00 → 16:30 Phenomenology

Président de session: Raffaele DAgnolo

14:00 Gravitational waves from axion strings

Orateur: Edward Hardy

Paris.pdf

15:00 Coffee break

15:30 Axions from the Quantum Gravity Viewpoint

Orateur: Matt Reece (Harvard)

2024_Reece_ENS_summer_institute.pdf

vendredi 28 juin

10:30 → 12:00 Phenomenology

Président de session: Raffaele DAgnolo

10:30 Coffee break

11:00 The Piezoaxionic Effect: dark matter detection and new forces

Orateur: Amalia Madden (Perimeter Institute)

ENS summer insitute 2024.pdf

14:00 → 15:30 Phenomenology

Président de session: Kallia Petraki (ENS and Sorbonne University)

14:00 DETOX haloscope first results

Orateur: Arnaud Thery (ENS)

talk_Thery_ENSb.pdf

15:00 Coffee break