LAPTh

PhD presentations
2025-09-11 08:00 - 10:00 UTC | Auditorium Vivargent (LAPTh)
Matthieu Bouchet
Rubin Zatini
Damien Leflot
Michail Tagaris
https://indico.in2p3.fr/event/36607/

3rd Training School COST Action COSMIC WISPers (CA21106)
2025-09-16 06:00 - 2025-09-19 20:30 | Auditorium Vivargent (Campus du CNRS)
Registration deadline extended until the 06/06/2025!

The COST Action CA21106 3rd Training School will be held in Annecy (France) at the LAPTh, a world-class research laboratory just 40 km away from CERN.

We will support travel and accommodation expenses of up to 30 participants.
Very likely, a visit to CERN will be organised on the 17th of September.
The goal is to start training a generation of young scientists in the interdisciplinary expertise on WISPs, ranging from theoretical and experimental approaches to multi-messenger astroparticle physics and cosmology. For this purpose, the Training School will offer lectures from experts on different aspects of WISPs physics. The School is aimed at PhD students, as well as at early-career postdocs.
The European COST Action CA21106 “Cosmic WISPers in the Dark Universe: Theory, astrophysics and experiments” is an initiative funded by the COST Association, whose goal is to study axions and other very weakly interacting slim particles (WISPs) emerging in several extensions of the Standard Model of Particle Physics. Searches for WISPs are strongly motivated by our attempts to understand the nature of the dark matter and puzzling astrophysical and particle physics observations.

https://indico.in2p3.fr/event/35550/

Jérémie Quevillon
2025-09-30 09:00 - 10:00 | Salle de Sommets
Speakers: Jérémie Quevillon (LAPTh Annecy)
https://indico.in2p3.fr/event/36095/

Testing cosmic reheating with primordial gravitational waves
2025-10-02 09:00 - 10:00 | Auditorium Vivargent (LAPTh)
Speakers: Nicolás BERNAL (CFTP – IST)
https://indico.in2p3.fr/event/36664/

Journée Théorie du CPTGA 2025
2025-10-08 06:00 - 15:05 | Auditorium (LAPTh)
Le CPTGA vous invite à sa 16ème “Journée de Physique Théorique”.
Le but de ces journées est de permettre des échanges entre physicien.ne.s théoricien.ne.s de Grenoble/Annecy travaillant dans des domaines très variés. Il est à la fois question de comprendre de la belle science et de découvrir le travail des collègues locaux.
Le thème de la Journée Théorie 2025 est “Physique (et) Statistique”
Le programme sur le site web est provisoire. Il sera complété au fur et à mesure.Merci de s’inscrire avant le 26 septembre 2025.==========================================
The CPTGA invites you to its 16th “Theoretical Physics Day.”
The aim of these days is to foster exchanges between theoretical physicists from Grenoble/Annecy working in a wide range of fields. It is both an opportunity to explore beautiful science and to discover the work of local colleagues.
The theme of the 2025 Theoretical Physics Day is “Physics (and) Statistics.”
The program on the website is provisional and will be updated progressively.
Please register before September 26, 2025.
https://indico.in2p3.fr/event/36702/

Julio Para-Martinez (IHES)
2025-10-09 09:00 - 10:00 | Auditorium Vivargent (LAPTh)
https://indico.in2p3.fr/event/35667/

Yangian symmetry, GKZ equations and integrable Feynman graphs
2025-11-01 10:00 - 11:00 | Salle des Sommets (LAPTh)
Speakers: Fedor Levkovich-Maslyuk (Centre for Mathematical Science, City St George’s, University of London)
DATE IN DISCUSSIONWe extend the powerful property of Yangian invariance to a new large class of conformally invariant multi-loop Feynman integrals. This leads to new highly constraining differential equations for them, making integrability visible at the level of individual Feynman graphs. Our results apply to planar Feynman diagrams in any spacetime dimension dual to an arbitrary network of intersecting straight lines on a plane (Baxter lattice), with propagator powers determined by the geometry. The graphs we consider determine correlators in the recently proposed “loom” fishnet CFTs. The construction unifies and greatly extends the known special cases of Yangian invariance to likely the most general family of integrable scalar planar graphs. We also relate these equations in certain cases to famous GKZ (Gelfand-Kapranov-Zelevinsky) hypergeometric operators, opening the way to using new powerful solution methods.
https://indico.in2p3.fr/event/36410/

Strings & Cosmology Meeting
2025-12-10 07:00 - 2025-12-12 17:00 | Auditorium (LAPTh)
This 3 days workshop aims at gathering string theorists and cosmologists to discuss recent developments on the timely topics of:
Dark energy (cosmological constant or dynamical)
Hubble tension and early dark energy models
Inflation and CMB
Cosmological correlators
considering both observational constraints (including DES, DESI results, prospects from Euclid, LSST, and CMB observations) as well as theoretical constraints (cosmological model building, string theory realisations and swampland obstructions). Ample time will be given for discussions between the participants and members of the two communities. Recent related events include the String – Cosmo Day and the AES3L workshop. This workshop takes part in the Transverse Task Force activities of the GdR CoPhy.
The workshop will take place in the Auditorium of LAPTh in Annecy, France, from the 10th till the 12th December 2025.

Speakers and discussion conveners include:
Boris BollietPhilippe BraxRodrigo CalderonMichele CicoliAnne DavisMiguel EscuderoWilliam GiarèHarry GoodhewOliver JanssenAli Rida KhalifeMiguel MonteroGeorges ObiedSusha Parameswaran
Lucas PinolMargherita PuttiFilippo RevelloMickael RigaultNicole RighiIgnacio RuizNils SchönebergGary ShiuAdam SmithElsa TeixeiraFlavio TonioniJean-Philippe UzanThomas Van RietDenis Werth

Public outreach talk: On Wednesday 10th December, there will be a public event from 17h until 19h, including at 18h a public outreach talk in French by Thibaut Coudarchet. This is part of “Les Mercredis du LAPP et du LAPTh”.

Registration: is open from the 8th September till the 12th November (or earlier if filled). Registration is mandatory for participation. For organisational reasons, unfortunately, we cannot accept more than about 80 participants. Therefore, each registration will be subject to approval, and confirmation will be sent. Priority will be given to experts in the field.

Contributed talks: we offer the possibility to young participants to propose a contributed talk of 20 minutes, including questions. This is done together with the registration. This call will be open from the 08th September till the 03rd October 2025, after which we will proceed with a selection.

Coffee, 3 lunches and 1 workshop dinner: those will be offered to registered participants. Attendance is asked during registration. Coffee and lunches take place at LAPTh. The workshop dinner will take place on Thursday 11th December at 19:30 at the restaurant Bleu Imperial. To reach the dinner restaurant as a group, we will leave LAPTh and catch the Bus 1 at Campus (18:41 or 18:53), stop at Montremont and walk along Avenue de France.

Accommodation: we recommend Hotel de Bonlieu, Allobroges Park Hotel or Moxy Annecy, even though many other hotels are possible in Annecy. Speakers and discussion conveners get two nights (10-12th Dec.) pre-booked and covered by us.

Travel information: nearby airports are in Geneva and Lyon. Annecy can also be reached by train (SNCF) or by bus (see below).
From Geneva airport as well as Geneva Cornavin train station, you can reach Annecy by train or by bus (272). It takes between 1:30 to 2 hours, and booking for both can be done on the Swiss train website. A faster option (45 mins), although traffic and border dependent, is by car. Other options are Flixbus (bus) or Blablacar (bus and car sharing).
From Lyon airport, you would have to take a fast tram to Lyon La Part Dieu train station. From there, you can take a train to Annecy (between 1:30 to 2 hours). Other options from Lyon are by car (1:30 hour) or again Flixbus or Blablacar.
Once at Annecy train and bus station, or from the city center, LAPTh can easily be reached by bus (e.g. with line 1, direction “Parc des Glaisins”, stop at “Campus”) following these instructions. It takes about 20 mins, and tickets can be bought with cash at the bus driver, or with a text message (SMS). SIBRA is the public transport website.
More travel information can also be found here. Travel expenses remain to be covered by participants.

Social activities: Annecy, with its lake and old city, deserves to be explored. At this time of the year, we also recommend the Christmas markets. In addition, the mountain surroundings offer ski resorts, sometimes reachable by public transport.

Disclaimer: Some registered participants have been contacted via phishing emails about their “hotel booking” or “reservation confirmation”. Please be careful, this is a scam.

Organisers: David Andriot, Vivian Poulin, Sébastien Renaux-Petel, Gary Shiu

Funding: CPTGA, CSAA CG, Enigmass+, EuCAPT, GdR CoPhy, IRN:QFS, LAPTh, LUPM, Owners of Annales H. Poincaré, Région AURA

https://indico.in2p3.fr/event/33661/

Entanglement and complexity of thermal states
2025-12-11 13:00 - 14:30 | Salle des fourmis (LAPTh)
Speakers: Samuel GARRATT (Princeton University)
Studies of entanglement in the ground states of many-body systems have provided insights into the relation between spatial correlations, low-energy spectral properties, and the computational resources required to describe a system. We know much less about entanglement in thermal equilibrium. This is because, at finite temperature, spatial correlations can be classical. In this talk I will show how entanglement in equilibrium is related to linear response. This relation allows for conventional experiments to detect how entanglement emerges on different length scales. I will then show how techniques from quantum statistical mechanics and field theory can be used to lower bound the resources necessary to prepare equilibrium states.
arXiv:2502.13218, arXiv:2510.02275
https://indico.in2p3.fr/event/37943/

Alek Bedroya - Holographic Constraints on the String Landscape
2026-01-14 15:00 - 16:00
Speakers: Alek Bedroya (Princeton University)
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Abstract: I will discuss scale separation in top-down string theory constructions of AdS vacua, focusing on proposals based on compactifications on Ricci-flat manifolds such as DGKT and KKLT. I will then present a general argument that the putative CFT duals of such scale-separated AdS vacua cannot emerge as infrared limits of any brane configuration in string theory, implying that such vacua are unlikely to be UV complete. This explains why stable AdS vacua in string theory are essentially higher-dimensional in nature. If time permits, I will conclude with further holographic constraints on scalar potentials with implications for cosmology.
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/38157/

Testing unification and the heterotic string with the axion-photon coupling
2026-01-15 10:00 - 11:00 | Salle des Sommets
Speakers: Mario Reig Lopez (Cern)
The topological nature of axion couplings to gauge bosons offers unique opportunities to obtain information about the UV limit of the SM. I will discuss why the discovery of an axion-like particle above the QCD line would rule out grand unified theories and the perturbative heterotic string.
Based on 2206.07053, 2410.03820 and 2509.08042.
https://indico.in2p3.fr/event/37948/

Geneviève Fest
2026-01-26 08:00 - 17:00 | Auditorium / Grande Galérie (LAPTh Annecy)
On the occasion of her retirement, a workshop to celebrate Geneviève Bélanger’s contributions to research, group building, and mentoring activities.
A tentative timetable is now available. Note that in addition to the scheduled review talks, there will be two “open mic” sessions open to all participants for their personal recollection, anecdotes, etc.
To join by Zoom: https://cern.zoom.us/j/63941389368?pwd=[REDACTED]
To contribute to the collective gift: https://www.papayoux.com/fr/cagnotte/genevieve-s-future-outdoor-adventures
https://indico.in2p3.fr/event/37768/

Journal Club
2026-01-27 10:00 - 11:00
see https://sdrive.cnrs.fr/s/NJmNfMtzFBfCkQy
https://indico.in2p3.fr/event/38460/

Ivano Basile - Horror vacui: instabilities in scale-separated Casimir compactifications
2026-01-28 15:00 - 16:00
Speakers: Ivano Basile (Garching, Max Planck Inst.)
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Abstract: Finding reliable scale-separated vacua with no moduli in the string landscape is a considerable challenge, yet it is essential to connect string theory to our universe. Among several attempts, toroidal compactifications supported by fluxes and Casimir energy stand out for their simplicity and degree of parametric control. In particular, there exist simple such compactifications of eleven-dimensional supergravity leading to non-supersymmetric weakly curved anti-de Sitter solutions in four dimensions. I will show that these solutions are perturbatively (and non-perturbatively) unstable, and thus do not pertain to bona fide four-dimensional effective field theories.
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/38238/

Physique fondamentale à partir de la structure à grande échelle de l'Univers à travers / Fundamental physics from large-scale structure across cosmic times)
2026-01-29 13:00 - 15:30 | Auditorium (Annecy)
Speakers: Azadeh Moradinezhad (Laboratoire d’Annecy-le-Vieux de Physique Théorique (LAPTh))
Le modèle /CDM décrit remarquablement bien l’Univers observé, mais il ne rend pas compte de l’origine des structures ni de lanature du secteur sombre. La précision croissante des observations met en évidence des tensions pouvant signaler une nouvellephysique. Dans cet exposé, je présenterai mes travaux et mon programme à venir pour exploiter les structures à grande échelle etrechercher de telles signatures à partir de deux observables complémentaires : le regroupement des galaxies et la cartographie enintensité de raies spectrales (LIM). L’essentiel de l’information encore sous-exploitée se situe (i) aux petites échelles non linéaires, oùl’on peut réduire la variance d’échantillonnage en moyennant sur de nombreuses structures indépendantes, à condition de modélisercorrectement les non-linéarités et les effets baryoniques, et (ii) à grand décalage vers le rouge, où les fluctuations restent plusproches des conditions initiales. Je présenterai des avancées pour extraire l’information non gaussienne du regroupement etmontrerai comment la LIM mm/sub-mm étend les analyses de LSS à haut redshift/décalage vers le rouge grâce à une atténuationrobuste des premiers plans et une modélisation précise du signal. Je conclurai en montrant comment la complémentarité desprincipales sondes de la LSS peut être exploitée dans des analyses multi-sondes cohérentes pour une cosmologie de précisionrobuste au-delà de la limite gaussienne.
The /CDM model has been remarkably successful in describing the observed Universe, yet it does not explain the origin of structureor the nature of the dark sector. Growing observational precision is exposing tensions that may be early signs of new physics,offering dues to these puzzles. ln this talk, 1 will present my research over the last decade and outline my future program to exploitlarge-scale structure (LSS) to search for new-physics imprints using two complementary observables: galaxy clustering and lineintensitymapping (LIM). Much of the untapped information in LSS resides on small nonlinear scales, where averaging over manyindependent features of the cosmic web can beat down sample variance if nonlinear and baryonic effects are modeled accurately,and at high redshifts, where fluctuations remain doser to the initial conditions. 1 will present advances in extracting non-Gaussianinformation from nonlinear clustering and show how mm/sub-mm LIM extends LSS analyses to the high-redshift Universe throughrobust foreground mitigation and accurate signal modeling. 1 will conclude by outlining how the complementarity of key LSS probescan be leveraged in coherent multi-probe analyses for robust precision cosmology beyond the Gaussian limit.
https://indico.in2p3.fr/event/38478/

Simulations and modeling for precision cosmology
2026-01-30 10:00 - 11:00 | Auditorium Vivargent (LAPTh)
Speakers: Zarija Lukic
Ongoing and upcoming cosmology surveys aim to address some of the deepest questions in fundamental physics—from the nature of dark energy and dark matter to tests of gravity and particle physics on the largest observable scales. Interpreting these data, which probe multiple cosmic epochs and physical scales, is a formidable challenge: it is fundamentally an inverse problem in which we infer the underlying physics from imperfect, biased, and noisy observations. In this talk I will describe our simulation and modeling program at Berkeley Lab’s Computational Cosmology Center to support inference using Lyman-α forest and intergalactic medium measurements. We have developed Nyx, a highly efficient and scalable cosmological hydrodynamics code, to generate high-fidelity realizations needed to connect theory to data, such as DESI observations. However, producing suites of full-physics simulations at the required accuracy remains computationally expensive, motivating complementary approaches. I will discuss our work on emulators—surrogate models trained on finite ensembles of simulations—as well as new hybrid strategies that combine physical modeling with generative ML/AI approaches.
https://indico.in2p3.fr/event/38053/

Repas de Noel
2026-02-05 09:00 - 16:00
https://indico.in2p3.fr/event/38246/

Hommage à Richard Taillet
2026-02-06 08:00 - 21:00
L’UFR Science et Montagne (SceM) et le Laboratoire d’Annecy de Physique Théorique (LAPTh) de l’Université Savoie Mont Blanc organisent une journée en hommage à notre collègue Richard Taillet, qui nous a quitté en été 2025.
Cette journée sera l’occasion de nous remémorer un collègue engagé et apprécié, autant sur le plan de la recherche, de l’enseignement, de l’engagement au sein de notre établissement et de la vulgarisation scientifique, que sur le plan personnel.
La capacité des salles étant limitée, l’inscription est nécessaire si vous souhaitez participer en personne à la journée. Un formulaire de demande d’inscription est à votre disposition en ligne sur cette page. Les inscriptions seront confirmées dans la limite des places disponibles.
https://indico.in2p3.fr/event/38226/

Journée hommage à Richard Taillet
2026-02-06 09:00 - 16:00
Plus d’information
https://indico.in2p3.fr/event/37826/

Gravitational probes of dark matter: off the beaten path
2026-02-12 10:00 - 11:00 | Auditorium Vivargent (LAPTh)
Speakers: Kfir Blum (weizmann institute of science)
Many astrophysical and cosmological systems show compelling positive evidence for the existence of dark matter. Yet, as all of this positive evidence is based on gravitational effects, the fundamental particle nature of dark matter remains unknown, hidden behind the veil of the equivalence principle. I will discuss attempts to penetrate this veil, still focusing on gravitational dynamics alone. First, I consider ultralight dark matter, a regime that arises if dark matter particles are so light that their de-Broglie wavelength attains astronomical scales. Dark matter in this regime can be constrained by detailed analyses of stellar distributions in galaxies of various shapes and sizes, and can also leave an imprint in gravitational lensing observations. Second, I consider, more broadly, the phenomenon of gravitational dynamical friction, which offers a probe of dark matter beyond the mean-field level, and — in some systems — provides compelling new evidence for dark matter in galaxies, qualitatively different and independent from traditional stellar kinematics.

https://indico.in2p3.fr/event/38255/

Journal Club
2026-02-17 10:00 - 11:00
see https://sdrive.cnrs.fr/s/NJmNfMtzFBfCkQy
https://indico.in2p3.fr/event/38461/

Naman Agarwal - Toward an Effective Theory of the Volume Modulus
2026-02-25 15:00 - 16:00
Speakers: Naman Agarwal (University of Manitoba)
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Abstract: In this talk, I will talk about my recent work with collaborators where we investigate the 4-dimensional effective theory of the warped volume modulus in the presence of stabilizing effects from gaugino condensation by analyzing the linearized 10-dimensional supergravity equations of motion. Warping is generally expected to scale down the masses of bulk modes to the IR scale at the tip of a throat. We find that the mass of the warped volume modulus evades expectations and is largely insensitive to the effects of warping, even in strongly warped backgrounds. Instead, the mass is parametrically tied to the 4-dimensional AdS curvature scale m2∼O(1)R^AdSm2∼O(1)R^AdS​, presenting a challenge for scale separation in these backgrounds. We trace this effect to a universal contribution arising from the 10-dimensional equations of motion, and comment on the importance of a 10-dimensional treatment of the warped volume modulus for effective field theories and model building.
Link: Zoom
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/38783/

Integrable boundary-driven quantum circuits with different geometries
2026-02-26 10:00 - 11:00 | Auditorium Vivargent (LAPTh)
Speakers: Ana Retore (DESY)
A quantum circuit is a way to simulate the time evolution of many-body operators where the scattering can be factorized into two body scattering operators for the bulk and one body operators for the boundaries. Integrability is a property where the presence of hidden symmetries in a model gives rise to a powerful toolkit to solve this model. This talk brings these two concepts together.
Integrability in a quantum circuit means that the circuit time evolution commutes with the conserved charges of the model giving rise to many tools to solve this model.They present several advantages, including reduced noise propagation when compared to non-integrable circuits, as well as the possibility to use integrability-based techniques to understand transport properties of quantum many-body systems.
These features motivated us to systematically classify integrable quantum circuits with open boundary conditions. In this talk, after an introduction to quantum circuits and their importance, I will present a construction of integrable boundary-driven quantum circuits with different geometries (positions of the gates) and discuss some examples.

https://indico.in2p3.fr/event/38028/

Journal Club
2026-03-03 10:00 - 11:00
see https://sdrive.cnrs.fr/s/NJmNfMtzFBfCkQy
https://indico.in2p3.fr/event/38462/

Colliders in the Sky: Constraining High-Energy Physics with CMB and LSS Observations
2026-03-05 10:00 - 11:00 | Salle des Sommets (LAPTh)
Speakers: Oliver Philcox (Stanford University)
Inflation is amongst the most mysterious phenomena in physics. With an energy scale potentially reaching 10^13 TeV, its physical description likely lies far beyond the realm of the standard model. This leaves many questions unanswered: what fields were present during inflation? how did they interact with each other? In this talk, I will discuss how modern cosmological datasets can be used to shed light on the early Universe by searching for the tell-tale signs of “primordial non-Gaussianity”. In particular, I will present new searches for inflationary signals in Cosmic Microwave Background and Galaxy Survey data, which allow for a detailed study of the primordial three- and four-point functions. Leveraging an array of theoretical and computational tricks, these methods can place constraints on the microphysics of inflation and directly probe particle scattering processes in the early Universe, acting as a “cosmological collider”. I will close by discussing future avenues of exploration and prospects for upcoming galaxy surveys.
https://indico.in2p3.fr/event/38090/

2nd UNDARK School: The multi-messenger non-thermal universe
2026-03-09 07:00 - 2026-03-13 17:00 | Auditorium Vivargent (Campus du CNRS)
The UNDARK’s Second Scientific School will be held in Annecy (France) at the LAPTh, a world-class research laboratory just 40 km away from CERN, from the 9th – 13th March 2026.

UNDARK Scientific Schools are week-long events aimed at equipping PhD students in the field of astroparticle physics with theoretical, phenomenological and numerical tools at the forefront of their field of research. The 2nd UNDARK Scientific School will focus on the multi-messenger non-thermal universe, including astrophysics of radio to gamma-ray observations and tests of fundamental physics.
No fee will be charged to participating students. A maximum of 30 students will be accepted. Coffee breaks, lunches and up to two dinners will be offered to the participants.Upon request and depending on funding, a few travel grants will be awarded to students.
The UNDARK consortium, where UNDARK stands for Unravelling the Dark Universe from the Canary islands Observatories, aims at resolving the constituents and the laws which govern this dark side of the universe. The consortium is led by the IAC, in partnership with CERN, IFAE, WIS and LAPTh. More information can be found in the UNDARK’s website.
UNDARK’s first school was organized by IFAE and held at the Benasque Science Center (Benasque, Spain) from March 9 to March 15, 2025.

Graphic design: Ève Barlier, UNDARK, 2025

School Picture 1
School Picture 2

https://indico.in2p3.fr/event/36693/

Journal Club
2026-03-17 10:00 - 11:00
see https://sdrive.cnrs.fr/s/NJmNfMtzFBfCkQy
https://indico.in2p3.fr/event/38463/

Victor Franken - Holographic quantum tasks in the static patch
2026-03-18 15:00 - 16:00
Speakers: Victor Franken (Gent Univ.)
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Abstract: In the AdS/CFT correspondence, direct scattering in the bulk may not have a local boundary analog. A nonlocal implementation on the boundary requires O(1/G​) mutual information. This statement is formalized by the connected wedge theorem, which can be proven using general relativity within AdS_3​ but also by applying quantum information theory on the boundary, suggesting that the theorem applies to any holographic duality. We examine scattering within the static patch of asymptotically dS_3 spacetime, which is conjectured to be described by a quantum theory on the stretched horizon in static patch holography. We prove that causality on the horizon should be induced from null infinities to maintain consistency with the theorem. Specifically, signals propagating in the static patch are associated with local operators at null infinity. These results suggest a novel connection between static patch holography and the dS/CFT correspondence.
Link: Visio
AnLy: https://sites.google.com/view/anlystringsandfields

https://indico.in2p3.fr/event/39166/

Journal Club
2026-03-31 09:00 - 10:00
see https://sdrive.cnrs.fr/s/NJmNfMtzFBfCkQy
https://indico.in2p3.fr/event/38464/

Abhishek MANIYAR
2026-04-02 09:00 - 10:00 | Auditorium Vivargent (LAPTh)
Speakers: Abhishek Maniyar (CNRS – LAPTh)
TBA
https://indico.in2p3.fr/event/39119/
