Jakob Moritz - De Sitter candidates in string theory
2024-11-27 15:00 - 16:00 UTC
Speakers: Jakob Moritz (CERN)
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Abstract: The simplest cosmology compatible with the accelerated expansion of our universe is de Sitter space. Yet, more than 25 years after the discovery of “dark energy’’, concrete de Sitter vacua of string theory have remained elusive. In this talk I will present the first fully concrete string compactifications that yield, at leading order in the string loop and α’α’ expansions, de Sitter vacua of a form envisioned by Kachru, Kallosh, Linde and Trivedi (KKLT) more than 20 years ago. I will begin by reviewing the KKLT proposal and its complex set of delicately balanced ingredients. Then, I will show how all the required features come together in actual examples: I will define explicit Calabi-Yau orientifolds and choices of quantized fluxes, and derive the corresponding four-dimensional effective supergravity theories. Each example includes a strongly warped “Klebanov-Strassler throat” region containing a single anti-D3-brane, whose supersymmetry-breaking energy, computed at leading order in α′, causes an uplift to a metastable de Sitter vacuum in which all moduli are stabilized. I will conclude by emphasizing a set of outstanding computational problems that need to be overcome in order to determine whether these vacua survive (presently unknown) subleading corrections, and thus promote to full solutions of string theory.
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/34412/

Positivity Constraints for condensed matter and cosmology
2024-11-28 10:00 - 11:00 | Auditorium Vivargent (CNRS Annecy)
Speakers: Paolo Creminelli (ICTP, Trieste)
The coefficients of the operators of an effective field theory (EFT) are constrained to satisfy certain inequalities, under the (mild) assumption that the UV completion satisfies general requirements of causality and unitarity. I discuss the extension of these ideas to theories where the Lorentz symmetry is spontaneously broken, as it happens in cosmology and condensed matter physics. I explain why the use of the S-Matrix run into immediate problems. Constraints can be derived using dispersive arguments for the 2-point function of conserved currents. As a concrete application I will discuss general bounds on the electromagnetic properties of media.
https://indico.in2p3.fr/event/34182/

AnLy 5th in-person Meeting
2024-12-03 07:00 - 18:00 | ENS Lyon
This is the 5th instance of the in-person AnLy meetings between neighboring institutions (IP2I Lyon, LAPTh Annecy, LPENSL Lyon) on string and field theory topics. It will take place at ENS Lyon, room MGN1-103 (1st floor, research side), on the 03rd December 2024.

Travel: Options between Lyon and Annecy are train (or train + bus), Flixbus, or car (and car-sharing).
Recommended trains: 07:43 (Annecy)-09:52 (Lyon Part-Dieu); 18:08 (Lyon Part-Dieu)-20:15 (Annecy)

Lunch: It will be provided to registered participants of the meeting.

Registration: It opens on the 08th Oct. and closes on the 14th Nov. 2024.

https://indico.in2p3.fr/event/34144/

Entanglement and quantum phase transitions : An introduction
2024-12-05 10:00 - 11:00 | Salle de Sommets
Speakers: Gilles Parez
As you may know, my research interests lie at the intersection of integrable systems and quantum information. This JC will be the occasion for me to give a *literal* introduction to the latter.
Many papers (and grant proposal) about quantum information and quantum entanglement in many-body systems contain a version of the following sentence in their introduction:
“It is very efficient to use quantities originally defined in the context of quantum information, such as entanglement measures, to detect and characterize quantum phase transitions in many-body systems. ”
In this JC, I will explain the meaning of this sentence, assuming no knowledge on quantum entanglement, by reviewing relevant seminal papers, and discuss some new exciting results in the field.
https://indico.in2p3.fr/event/34012/

Entanglement and quantum phase transitions : An introduction
2024-12-05 10:00 - 11:00 | Salle des Sommets (LAPTh)
Speakers: Gilles Parez (Lapth)
Many papers (and grant proposal) about quantum information and quantum entanglement in many-body systems contain a version of the following sentence in their introduction:
“It is very efficient to use quantities originally defined in the context of quantum information, such as entanglement measures, to detect and characterize quantum phase transitions in many-body systems. ”
In this JC, I will explain the meaning of this sentence, assuming no knowledge on quantum entanglement, by reviewing relevant seminal papers, and discuss some new exciting results in the field.
https://indico.in2p3.fr/event/34805/

Felipe Figueroa
2024-12-10 13:00 - 15:30 | Auditorium (Annecy-le-Vieux)
https://indico.in2p3.fr/event/33909/

Philippe Brax - Axio-dilaton screened cosmology
2024-12-11 15:00 - 16:00
Speakers: Philippe Brax (CEA)
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Abstract: I will review the problems caused by light scalar fields in particular with respect to gravitational tests and consider a new type of screening mechanism which allows to evade them. This involves two fields, an axion-like field and a dilaton, for which I will also present new results on their cosmology and a link to early dark energy.
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/34608/

Le Futur Collisionneur Circulaire: Pourquoi ? Quand ? Comment ?
2024-12-13 13:30 - 15:30 | Auditorium Vivargent (LAPP / LAPTh)
Speakers: Christophe Grojean (DESY (Hamburg) and Humboldt University (Berlin))
Le futur collisionneur circulaire se profile comme le prochain grand défi scientifique à relever. Son programme ambitieux devrait occuper la physique des hautes énergies pour les décennies à venir. Qu’il s’agisse d’explorer le modèle standard avec une précision sans précédent ou de rechercher de nouvelles particules, cette machine est conçue avec la polyvalence et la diversité au cœur de son programme échelonnée en plusieurs étapes. Cette présentation visera à donner un aperçu de l’état actuel du projet. L’accent sera mis sur les aspects physiques, en particulier ceux de la phase initiale avec des collisions d’électrons et de positons.
Future Circular Collider: What? Why? When? The Future Circular Collider program is profiling itself as the next big challenge taken up by fundamental science. This ambitious program would be a unique opportunity to fuel the field of high-energy physics for several decades to come. Be it for exploring the standard model with unprecedented precision or to search for new physics, this machine is being designed with versatility and diversity at the heart of its multi-stage program. This presentation will aim at providing a snapshot at the current state of affairs. Emphasis will be given on the physics case, particularly for the early stage with electron-positron collisions.
https://indico.in2p3.fr/event/34934/

Marco Chianese
2025-01-16 10:00 - 11:00 | Salle des Sommets (LAPTh)
https://indico.in2p3.fr/event/34675/

Marko Pesut
2025-01-23 10:00 - 11:00 | Salle des Sommets (LAPTh)
https://indico.in2p3.fr/event/34676/

Chris Hull
2025-01-29 15:00 - 16:00
Speakers: Chris Hull (Imperial College)
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Abstract:
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/35004/

Julien Lavalle
2025-01-30 10:00 - 11:00 | Salle des Sommets (LAPTh)
https://indico.in2p3.fr/event/34677/

RPP 2025
2025-02-05 12:30 - 2025-02-07 17:00 | Auditorium Vivargent (Laboratoire d’Annecy de Physique Théorique (LAPTh))
The Rencontres de Physique des Particules (RPP) are the annual general meeting of the French community in theoretical high-energy physics. It dwells into the deepest puzzles posed by our current understanding of the fundamental structure of matter and the history of our Universe. Aiming at pushing further the frontier of knowledge.
The Laboratoire d’Annecy de Physique Theorique (LAPTh) is delighted to host the RPP’s 2025 edition from February 5th to 7th in Annecy. The local organising committee is composed of Geneviève Bélanger, Cédric Delaunay, Diego Guadagnoli and Jérémie Quevillon, as well as Dominique Turc, Véronique Jonnery and Virginie Malaval for the administrative part.
The sessions will open with an invited review lecture, followed by selected highlights of the latest development in the field.
Confirmed invited speakers include :
Francesca Calore (LAPTh)
Yann Mambrini (IJCLab)
Méril Reboud (IJCLab)
Adam Falkowski (IJCLab)
Quentin Bonnefoy (IPHC)
Participants are kindly invited to register here at their earliest convenience until January 15th.
Those interested to give a talk on their research, please submit your abstract here before January 8th.

Organising Committee:
Geneviève BélangerCédric DelaunayDiego GuadagnoliJérémie Quevillon
Véronique Jonnery (admin)Virginie Malaval (admin)Dominique Turc (admin head)

Funding sources: LAPTh, CPTGA, Enigmass+

https://indico.in2p3.fr/event/34316/

Irene Tamborra
2025-02-06 10:00 - 11:00 | Salle des Sommets (LAPTh)
https://indico.in2p3.fr/event/33937/

Exploring Singularities of Integrals from Physics via Computational Algebraic Geometry
2025-02-20 10:00 - 11:00 | Auditorium Vivargent (LAPTh)
Speakers: Claudia Fevola (Inria-Saclay)
Feynman integrals play a central role in particle physics, particularly in the theory of scattering amplitudes. A key challenge lies in identifying the values of physical parameters at which a given integral develops singularities. In this talk, I will present examples demonstrating how the interplay between algebro-geometric methods and fundamental physics problems drives advances in both fields. I will discuss theoretical and practical methods for studying the singularities of Feynman integrals and provide explicit formulas for the specific case of integrals of products of linear polynomials, inspired by applications in theoretical cosmology. This work is based on collaborations with Saiei Matsubara-Heo, Sebastian Mizera, and Simon Telen.
https://indico.in2p3.fr/event/35295/

Oliver Schlotterer
2025-02-27 10:00 - 11:00 | Auditorium Vivargent (LAPTh)
Speakers: Oliver Schlotterer (Uppsala Universitet)
https://indico.in2p3.fr/event/35296/

Moving cosmological data analysis forward with differentiable forward models
2025-03-04 10:00 - 11:00
Speakers: Thomas Floss (University of Vienna)
Cosmology is about to receive a large influx of a variety of observational data, providing a promising avenue for addressing some of the most critical questions in fundamental physics. In this seminar, I will give a brief introduction to some of the concepts used in standard cosmological data analysis.I will then discuss some recent work on developing more optimal methods of extracting cosmological information from data using differentiable forward models, with the goal of maximizing the scientific potential of cosmological surveys.
https://indico.in2p3.fr/event/35725/

New frontiers of Feynman Integral Computations: Mathematical Structures in Phenomenology
2025-03-06 10:00 - 11:00 | Salle des Sommets (LAPTh)
Speakers: Ekta Chaubey (U. Bonn)
In this talk, I will discuss how to advance the mathematical understandingof multi-loop, multi-leg, and multi-scale Feynman integrals and to bridgethe gap between the mathematical framework of scattering amplitudes andtheir phenomenological applications. I will highlight their broad relevance,not only in achieving groundbreaking predictions for LHC observations butalso in extending their impact beyond elementary particle physics. Forinstance, these computations play a crucial role in the precise calculationof bound-state observables and have contributed to breakthroughs ingravitational wave research.
https://indico.in2p3.fr/event/35573/

Miguel Montero - The DGKT scenario and the Weak Gravity Conjecture
2025-03-12 15:00 - 16:00
Speakers: Miguel Montero (IFT Madrid)
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Abstract: I will discuss how generic quantum corrections lift the moduli space of BPS branes in 4d N=1 scale-separated solutions like DGKT. This means that there is a tension between this scenario and the WGC for membranes, which demands the existence of an exactly extremal brane. Similar tensions exist in any 4d N=1 scenario not protected by a parity symmetry, and I will mention some examples.
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/35506/

New Physics from the “Hubble Tension”
2025-03-13 10:00 - 11:00 | Auditorium Vivargent (LAPTh)
Speakers: Vivian Poulin (LUPM (CNRS & U. de Montpellier))
Over the last decade, measurements of the expansion rate of the universe today, H0, made with cepheid-calibrated SN1a have become increasingly discrepant with the value predicted from the ΛCDM model when fit to CMB data. After a brief review of the experimental situation, I will show the potential implications of this “Hubble tension” for new physics. I will argue that it points to some new mechanism at play in the pre- recombination universe (i.e., z > 1000), rather than a new dynamical effect at late-time (i.e. 0 < z < 1). I will discuss some model-independent implications of the Hubble tension that can help shed light on its origin.
https://indico.in2p3.fr/event/35427/

A probabilistic approach to Toda Conformal Field Theories
2025-03-20 10:00 - 11:00 | Auditorium Vivargent (LAPTh)
Speakers: Baptiste Cerclé (EPFL)
Conformal invariance is a feature that arises for a large class of models of statistical physics at criticality. To address the issue of understanding the conformal field theory (CFT) thus defined, Belavin-Polyakov-Zamolodchikov designed in 1984 a general method for solving such a theory, dubbed conformal bootstrap. However there is a large class of models, such as the critical three-states Potts model, that enjoy in addition to conformal invariance an enhanced level of symmetry called higher-spin symmetry. Capturing this feature led to the introduction by Zamolodchikov of the notion of W-algebras, which are Vertex Algebras containing the Virasoro algebra.

In this talk we will explain how this higher-spin symmetry manifests itself for Toda CFTs, generalizations of Liouville CFT that enjoy this higher level of symmetry. Namely in a first part we will explain how probability theory allows to define rigorously such models. We will then explain how this symmetry manifests itself within this probabilistic framework and describe some of its implications, such as the computation of a family of correlation functions of the theory.
https://indico.in2p3.fr/event/35896/

Marios Petropoulos
2025-03-26 13:00 - 14:00 | Auditorium Vivargent (LAPTh)
https://indico.in2p3.fr/event/35662/

Niall Macpherson
2025-03-26 15:00 - 16:00
Speakers: Niall Macpherson (Oviedo Univ.)
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Abstract:
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/35526/

Rafael Alves Batista
2025-03-27 10:00 - 11:00 | Auditorium Vivargent (LAPTh)
Speakers: Rafael Alves Batista
https://indico.in2p3.fr/event/35589/

Implications of $B^+ to K^+ ubar u$ under rank-one flavour violation hypothesis
2025-04-01 09:00 - 10:00 | Salle de Sommets
Speakers: Claudio Toni
We study the implications of the observed excess at Belle-II under the assumption of Rank-One Flavour Violation, i.e. that New Physics couples to a single specific direction in flavour space. By varying this direction we perform analyses at the level of the low-energy EFT, the SMEFT, and with explicit mediators such as leptoquarks and colorless vectors. Among the various mediators, the scalar leptoquarks $tilde{R}_2$ and $S_1$ offer the best fits of the Belle-II excess, while being consistent with the other bounds. On the other hand, colorless vectors are strongly constrained by meson mixing and resonance searches. In all cases we find that a flavour alignment close to the third generation is generically preferred.
https://indico.in2p3.fr/event/36029/

Taming projection effects in EFT of LSS analysis of DESI
2025-04-03 09:00 - 10:00 | Auditorium Vivargent (LAPTh)
Speakers: Marco Bonici (INAF-IASF Milano)
The analysis of galaxy clustering measurements from surveys like Euclid or DESI is likely to be affected by the so-called projection effects, which causes the 1D marginals of the analysis to not contain the bestfit; this is a serious issue which can potentially harm the cosmological interpretation of these analyses. In this talk I will present a few avenues to tackle this issue, either using simulation-calibrated priors, a frequentist framework, or a bayesian reparametrization approach. All of these approaches can significantly reduce the projection effects, following different strategies.
Specifically, I will show the ongoing application of these methods to current DESI DR1 data, and will compare the results among them and with the baseline DESI analysis.
https://indico.in2p3.fr/event/35426/

L’héliocentrisme selon Copernic
2025-04-04 12:00 - 14:00 | Auditorium Vivargent (LAPP / LAPTh)
Speakers: Richard Taillet (Université de Savoie/LAPTH)
L’hypothèse d’un univers héliocentrique formulée par Nicolas Copernic en 1543, en opposition au modèle géocentrique dit « de Ptolémée » et en vigueur depuis plus d’un millénaire, marque un tournant majeur dans notre conception du monde, au point que l’expression « révolution copernicienne » est entrée dans le langage courant. Toutefois, cet épisode de l’histoire des sciences est souvent présenté d’une manière caricaturale, qui ne permet pas de saisir pleinement la proposition copernicienne, avec ses forces et ses faiblesses. Lors de ce séminaire, destiné à des physiciens et physiciennes, Richard Taillet tentera de dresser un tableau détaillé du modèle héliocentrique, des problèmes qu’il avait vocation à résoudre, des oppositions qu’il a suscitées et des alternatives qui ont été avancées pendant le siècle qui a suivi.

https://indico.in2p3.fr/event/35666/

Zucheng Gao - Chasing parity-violating signature in large-scale structure cosmology
2025-04-08 09:00 - 10:00 | Salle de Sommets
Speakers: Zucheng Gao
Parity-violating has been found in the weak interactions. In cosmology, certain inflation mechanism can also introduce parity-violating imprints on the primordial fluctuations. Here we present theoretically how the parity-violating signature enters large-scale structure (LSS), based on Eulerian perturbation theory (EPT). We develop an effective estimator to extract parity-violating information from LSS. We test this estimator by performing both the theory calculation and the measurement on simulations. We also pin down the obstacles faced by LSS surveys before we can claim a detection of a primordial parity-violating signature.

https://indico.in2p3.fr/event/36088/

Daniele Oriti - Late-time cosmic acceleration from Quantum Gravity
2025-04-09 14:00 - 15:00
Speakers: Daniele Oriti (Universidad Complutense de Madrid)
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Abstract: We show how a cosmological dynamics with a late-time cosmic acceleration and an asymptotic deSitter regime can be obtained from hydrodynamics on minisuperspace, a framework generalising quantum cosmology with non-linear terms. We also show how this hydrodynamics framework can be derived from fundamental quantum gravity models within the tensorial group field theory formalism, an approach closely related to lattice quantum gravity and loop quantum gravity. If time allows, we discuss other results within the same framework, concerning emergent cosmological physics, as well as other research directions leading to it.
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/35680/

Introduction to generalised symmetries
2025-04-10 08:30 - 09:30 | Auditorium Vivargent (LAPTh)
Speakers: Clément Delcamp (IHES)
Defining internal symmetry in a quantum theory through the lens of topological defects has opened the door to generalised notions of symmetry. In this seminar, I will introduce such generalisations and sketch the relevant mathematical framework, before presenting explicit examples in quantum lattice models.
https://indico.in2p3.fr/event/35727/
