Pantheon SEMPARIS Le serveur des séminaires parisiens Paris

The SEMPARIS seminar webserver hosts annoucements of all seminars taking place in Paris area, in all topics of physics, mathematics and computer science. It allows registered users to receive a selection of announcements by email on a daily or weekly basis, and offers the possibility to archive PDF or Powerpoint files, making it available to the scientific community.   [ More information ]


Upcoming Seminars [Next 30 ]
[ scheduler view ]

Friday 1 March 2024, 10:00 at IPHT, Salle Claude Itzykson, Bât. 774 COURS (Cours) physics
Sylvain Ribault ( IPhT ) Exactly solvable 2D conformal field theories
Abstract: Abstract: In this course, we review two-dimensional CFT in the bootstrap approach, and sketch the known exactly solvable CFTs with no extended chiral symmetry: Liouville theory, (generalized) minimal models, limits thereof, and loop models, including the O(n), Potts and U(n) models. Exact solvability relies on local conformal symmetry, and on the existence of degenerate fields: we explain how these assumptions constrain the spectrum and correlation functions. We discuss the crossing symmetry equations, and how they can be solved analytically or numerically, leading to analytic formulas for structure constants. \\ \\ In the case of loop models, we review the combinatorial description of correlation functions, inspired by the lattice construction of statistical models. We sketch what remains to be done for solving the models. \\ \\ The plan is: \\ 1. The Virasoro algebra and its representations. Fields and operator product expansions.\\ 2. Fusion rules and fusion products. Correlation functions and Ward identities. Crossing symmetry and conformal blocks.\\ 3. Defining a CFT. Diagonal and non-diagonal fields, degenerate fields. Exactly solvable CFTs and their spectrums.\\ 4. Degenerate 4-point functions. Analytic formulas for 2-point and 3-point structure constants.\_ 5. Computing conformal blocks. Numerical bootstrap.\\ 6. Correlation functions in loop models.\\ \\ Livestream on youtube.com/IPhT-TV: no subscription required.\\ Videoconference: subscribe to the course newsletter to receive links

Monday 4 March 2024, 10:45 at LPTMC, On Zoom SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée) cond-mat
Berislav Buca ( Niels Bohr Institute ) Non-stationary quantum many-body dynamics
Abstract: Non-stationary processes are special types of non-mixing dynamics characterised by long-time deterministic dynamics. They are ubiquitous in the real world around us - from biological to social phenomena. Likewise, on the quantum level, any successful long circuit depth calculation on a quantum computer is, by definition, non-stationary. Therefore, understanding how non-stationarity emerges from the microscopic quantum laws is of fundamental scientific and technological importance. I will discuss fully general algebraic theory that describes the long-time dynamics of a quantum many-body system, including non-stationary cases. The theory is full general and allows for exact solutions even in non-integrable systems provided that the relevant algebraic dynamical symmetries of the model can be identified. I give several physically relevant examples in both closed and open quantum many-body systems, including various quantum many-body scarred systems, a spin-1/2 Creutz ladder with oscillating out-of-time-order correlators, a spin-dephased Fermi-Hubbard model, and a two-component BEC in a lossy optical cavity which was recently experimentally studied and Hilbert space fragmented models. [1] B Buca, J Tindall, D Jaksch. Nat. Comms. 10 (1), 1730 (2019) [2] B Buca, D Jaksch. Phys. Rev. Lett. 123, 260401 (2019) [3] N Dogra, et al. Science, 366, 1496 (2019) [4] B Buca. Phys. Rev. Lett. 128, 100601 (2022). [5] B Buca. Phys. Rev. X 13, 031013 (2023)

Monday 4 March 2024, 11:00 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-PHM (Séminaire de physique mathématique) math-ph
Andreas Klumper ( Wuppertal ) Logarithmic corrections arising from non-linear integral equations with singular kernels
Abstract: Andreas Kluemper, Mouhcine Azhari We present recent results for the computational treatment of the spectra of the integrable staggered six-vertex model and the integrable $3-\bar 3$ superspin chain. The staggered six-vertex model has attracted the interest of several groups of authors who derived a wealth of results (e.g.~Ikhlef, Jacobsen, Saleur 08, 12

Tuesday 5 March 2024, 10:30 at IHES, Amphithéâtre Léon Motchane
( Cours de l'IHES )
MATH-IHES (TBA) math
Jonathan Pila ( University of Oxford et IHES ) Point-Counting and the Zilber-Pink Conjecture (3/4)
Abstract: The Zilber-Pink conjecture is a diophantine finiteness conjecture. It unifies and gives a far-reaching generalization of the classical Mordell-Lang and Andre-Oort conjectures, and is wide open in general. Point-counting results for definable sets in o-minimal structures provide a strategy for proving suitable cases which has had some success, in particular in its use in proving the Andre-Oort conjecture. The course will describe the Zilber-Pink conjecture and the point-counting approach to proving cases of it, eventually concentrating on the case of a curve in a power of the modular curve. We will describe the model-theoretic contexts of the conjectures and techniques, and the essential arithmetic ingredients.

Tuesday 5 March 2024, 11:00 at IPHT, Amphi Claude Bloch, Bât. 774 IPHT-GEN (Séminaire général du SPhT) physics
Clément Ranc ( IAP ) How gravitational microlensing constrains models of planet formation
Abstract: The Galactic Bulge Time Domain Survey of the NASA Nancy Grace Roman Space Telescope (launch in 2026/2027, formerly called WFIRST) will use the gravitational microlensing method to detect more than 1000 planets with masses as low as Mars mass around G, K and M stars. The high resolution capability and high precision photometry of the telescope will also yield the mass measurements of ~700 such planets and their host stars during its prime mission. In this talk, I will present the physical concepts and observational techniques behind this space survey, using results already obtained from ground observations, including from follow-up observations that enable a mass measurement of cold exoplanets on wide orbits (~0.5-10 AU). Past microlensing surveys have measured the planet-to-host star mass-ratio function of the cold exoplanets in the Milky Way. When compared to predictions from planet population synthesis models, these observational results question some stages of the models of giant planet formation. After discussing these results, I will present an ongoing program aiming at converting the aforementioned "mass-ratio function" into a "mass function" which is expected to provide new insights on the abundance of cold exoplanets, its dependence to the host-star mass and location in the galaxy.

Tuesday 5 March 2024, 11:00 at LPTMS, Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530 LPTMS (Séminaire du Laboratoire de Physique Théorique et Modèles Statistiques (Orsay)) cond-mat.stat-mech
Sergei Nechaev ( LPTMS ) Eastern and Western Mentalities as Golden and Silver Stationary Points in Probe Particle Dynamics within a Modular Domain
Abstract: We analyze flows generated by iterative dynamics of reflections of triangles. We interpret these flows as the probe particle adiabatic dynamics in the fundamental domain of the modular group. We consider two specific cases of lattices: (a) generated by reflections of equilateral triangles, and (b) generated by reflections of rectangular isosceles triangles. We show that stationary points of the flows for equilateral and isosceles triangles are correspondingly the « Golden » and the « Silver » ratios. We speculate about the manifestation of the difference between the Golden and the Silver ratios in cultural traditions of the « Western » and the « Eastern » world.

Tuesday 5 March 2024, 14:00 at IPHT, Salle Claude Itzykson, Bât. 774 IPHT-HEP (Séminaire de physique des particules et de cosmologie) hep-ph
Sebastian Ellis ( Université de Genève ) Tuning in to Radio Gravity
Abstract: The discovery of Gravitational Waves (GWs) has propelled us into a new age of astronomy. However, possibly even more interesting than the waves themselves, are their sources. In this talk we will first examine the scenarios predicting GWs in the radio band above kHz. We will see that such high-frequency GWs could provide a unique window into new physics. We will then demonstrate how existing and upcoming experiments targeting other signals can be recycled to search for Radio Gravity.

Tuesday 5 March 2024, 14:00 at LPENS, Conf IV-E244, 24 Rue Lhomond LPTENS-HE (Séminaire commun LPTENS-LPTHE) hep-th
Alexey Milekhin ( California Institute of Technology ) Sachdev-Ye-Kitaev model: from statistical mechanics to anti-de Sitter and de Sitter holographies
Abstract: I give an overview of the Sachdev-Ye-Kitaev model. Despite the simplicity of its Hamiltonian, it displays very rich physics with applications in both statistical mechanics and quantum gravity. And the end of my talk I will argue that a variant of this model also shares a lot of properties with de Sitter spacetime.

Tuesday 5 March 2024, 14:00 at IJCLAB, A018 NUC-THEO (Séminaire de physique nucléaire théorique) nucl-th
Guillaume Scamps ( LP2IT ) Why do the fission fragments spin?

Abstract: Recently, new measurements of the fission fragments’ spin showed no correlations between the fragments’ spin. These results have stimulated extensive theoretical discussion about the generation, orientation, and correlation of the fission fragments spin. In this contribution, I will discuss several approaches microscopical and collective to describe the mechanisms responsible for the angular momentum at scission. Although we currently have experimental data about the correlation between the magnitude of the angular momenta of the fragments, the presence of correlation between their direction described by the opening angle distribution is subject to different predictions from various theories. I will show how quantal effects and geometry of the scission configuration can change the opening angle distribution.
Attachments:
  • Abstract.pdf (139591 bytes) OPEN

Tuesday 5 March 2024, 14:00 at LPTHE, Library and Zoom (link in the comments) LPTHE-PPH (Particle Physics at LPTHE) hep-ph
Johannes Braathen ( DESY ) Cornering New Physics with precision calculations of Higgs-boson properties
Abstract: Thanks to the Higgs boson's close connection with many unsolved problems of Particle Physics, precision studies of Higgs properties constitute a crucial probe of Beyond-the-Standard Model (BSM) Physics. Among these properties, the trilinear Higgs coupling provides a unique opportunity to access the structure of the Higgs sector, investigate the nature of the electroweak phase transition and the origin of the baryon asymmetry of the Universe, and search for indirect signs of BSM Physics. I will show that the trilinear Higgs coupling can, in models with extended scalar sectors, be significantly enhanced with respect to its SM prediction. Consequently, the current experimental bounds on this coupling are already sufficient to rule out significant parts of the BSM parameter space that would otherwise be unconstrained by state-of-the-art theoretical and experimental constraints. Next, I will present the new public tool anyH3, which provides complete one-loop predictions for the trilinear Higgs coupling in arbitrary renormalisable theories. I will review the main features of anyH3 and present examples of new results obtained with it, as well as ongoing developments.

Wednesday 6 March 2024, 11:00 at CPHT, Louis Michel SEM-CPHT (Séminaire du CPHT) hep-th
Carlo Heissenberg ( Queen Mary University of London ) An eikonal approach to gravitational scattering and waveforms
Abstract: The classical limit of scattering amplitudes offers a convenient strategy to calculate gravitational-wave observables for binary processes in the post- Minkowskian (PM) regime, in which the two objects are far apart and interact weakly. In this talk I will discuss how the eikonal exponentiation offers a simple and conceptually transparent framework to exploit this connection and calculate key gravitational observables from amplitudes: the deflection angle for two-body encounters, energy and angular momentum losses, as well as the emitted gravitational waveform itself. The latter emerges in particular from the 2-to-3 amplitude for the scattering of two massive scalars and the emission of a graviton. I will briefly illustrate the calculation of its one-loop contribution, which is the key ingredient to obtain the first PM correction to the classic result obtained by Kovacs and Thorne in the 70s. Moreover, I will show how the choice of asymptotic BMS frame is crucial in order to compare the resulting amplitude-based waveform with the multipolar post-Newtonian (PN) one, in the small-velocity and soft limits, finding agreement up to 3PN order.

Wednesday 6 March 2024, 12:45 at LPENS, 3 rue dUlm FORUM-ENS (Forum de Physique Statistique @ ENS) cond-mat.stat-mech
Kay Wiese ( LPENS ) The critical dimensions of the Ising and Potts models and the complex CFT for Potts inside the first-order regime
Abstract: This talk will be based on the two recent works: https://arxiv.org/abs/2402.10732, and https://arxiv.org/abs/2311.01529 (based on 2402.10732 )

Wednesday 6 March 2024, 13:30 at DPT-PHYS-ENS, ConfIV (E244) - Dépt de Physique de l'ENS - 24 rue Lhomond 75005 PARIS COLLOQUIUM-ENS (Colloquium of the Physics Department of ENS) physics
Manuel Bibes CANCELLED. To be rescheduled later.
Abstract: TBA

Wednesday 6 March 2024, 14:00 at IJCLAB, Room 114 (Salle des Séminaires), Bat. 210, 1st floor IJCLAB-COSM (Seminar of the Gravity and cosmology group of IJCLAB) gr-qc
Serena Giardino ( Max Planck Institute for Gravitational Physics (Postdam), Heidelberg University ) Mapping the landscape of gravity theories
Abstract: Both Einstein's equations and the field equations of a modified theory of gravity can be derived as equations of state from purely thermodynamical considerations, leading to the identification of GR with an equilibrium state of gravity and modified gravity with a non-equilibrium one. This breakthrough made the relationship between gravity and thermodynamics even more intriguing. I will present a new approach to the thermodynamics of modified gravity which is inspired by these results, but follows a starkly different path. A precise description of the approach to equilibrium naturally emerges from using Eckart’s first-order irreversible thermodynamics on the effective imperfect fluid describing scalar-tensor gravity. Applications of this framework to cosmology, extensions to different classes of modified theories, and the formulation of two complementary descriptions based on the notions of temperature and chemical potential all contribute to a new and unifying picture of the landscape of gravity theories GR is embedded in.

Wednesday 6 March 2024, 14:00 at IJCLAB, A018 NUC-THEO (Séminaire de physique nucléaire théorique) nucl-th
Thibaud Dumont ( IPHC ) Nuclear reaction rates as a key ingredient of stellar modelling: The case of the C12+C12 fusion reaction
Abstract: The origin of elements as well as their abundance in the Universe and among stars is at the heart of astrophysics today. Since the Big Bang, chemicals abundances are continuously evolving due to the nucleosynthesis involving different processes with mainly nuclear fusion or particle capture and the subsequent reactions. These processes are taking place in a variety of astrophysical sites, from stars to supernovae and merging events. Stellar evolution codes have been developed to describe the evolution and structure of stars using different physical input ingredients. In particular, the precise determination of the nuclear reaction rates, that drive the stellar evolution, is a crucial ingredient in understanding chemical evolution. Recently, new nuclear reaction rates have been determined for the different stellar evolution phases by nuclear experiments, potentially leading to significant changes in the nucleosynthesis predictions, with consequences on light and s-process elements abundances. In order to improve stellar modeling, we now need to take into account these new results that can bring one of the key to better constrain stellar evolution and better understand the chemically peculiar stars. Especially I focus on the C12+C12 nuclear reaction that takes place during the C-burning phase of massive stars (> 8Msol) and for which new measurements have been obtained recently by the IPHC-STELLA team of Strasbourg.
Attachments:
  • Abstract.pdf (143773 bytes) OPEN

Wednesday 6 March 2024, 16:00 at IJCLAB, A243 NUC-THEO (Séminaire de physique nucléaire théorique) nucl-th
Neill Warrington ( MIT ) Laboratory Lattice Field Theory and Numerical Qubit Design
Abstract: I will present my recent work developing connections between precision quantum experiments and quantum many body physics. I will present lattice field theory calculations informing atomic gas experiments, then speculate a way to take a literal continuum limit in the lab. I will then present a numerical framework for qubit design.
Attachments:
  • Abstract.pdf (137563 bytes) OPEN

Thursday 7 March 2024, 11:00 at LPTHE, bibliothèque du LPTHE, tour 13-14, 4eme étage SEM-DARBOUX (Séminaire Darboux - physique théorique et mathématiques) hep-th|math.AG
Tudor Padurariu ( Laboratoire de Mathématiques d'Orsay, Université Paris-Saclay ) Quasi-BPS categories for K3 surfaces
Abstract: BPS invariants and cohomology are central objects in the study of (Kontsevich- Soibelman) Hall algebras or in enumerative geometry of Calabi-Yau 3-folds. In joint work with Yukinobu Toda, we introduce a categorical version of BPS cohomology for local K3 surfaces, called quasi-BPS categories. When the weight and the Mukai vector are coprime, the quasi-BPS category is smooth, proper, and with trivial Serre functor etale locally on the good moduli space. Thus quasi-BPS categories provide (twisted) categorical (etale locally) crepant resolutions of the moduli space of semistable sheaves on a K3 surface for generic stability condition and a general Mukai vector. Time permitting, I will also discuss a categorical version of the \chi-independence phenomenon for BPS invariants.

Thursday 7 March 2024, 14:00 at LPTMC, zoom: https://us06web.zoom.us/j/82091932293?pwd=zeSTGU68EkQWbN4z29E7alV9qf4o8C.1
( Join Zoom Meeting https://us06web.zoom.us/j/82091932293?pwd=zeSTGU68EkQWbN4z29E7alV9qf4o8C.1 Meeting ID: 820 9193 2293 Passcode: 798606 )
SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée) cond-mat
Bo Han ( Weizmann Institute ) Entanglement: Cornerstone of Quantum Phases and Transitions
Abstract: Entanglement is the unique property that sharply distinguishes quantum from classical physics. Quantum entanglement is the hallmark of quantum phases and transitions without symmetry breaking. Beyond the conceptual level, quantum entanglement is essential in quantum computing devices. By instilling entanglement into unentangled product states, physicists have realized topologically ordered phases with anyons and noisy intermediate-scale quantum (NISQ) devices in experiments. In this talk, I discuss two examples exhibiting an inseparable connection between entanglement and phases of matter. The first is the topologically ordered time crystal phase, which has been realized experimentally on quantum processors; the second is spin ladders with specific discrete symmetries, emulating 2D spinful bosons with long-range entanglement. I conclude with an outlook on how quantum entanglement reshapes science and technology in many-body physics.

Thursday 7 March 2024, 14:30 at IHES, Amphithéâtre Léon Motchane MATH-IHES (TBA) math
Claudia Rella ( Université de Genève ) Strong-Weak Duality and Quantum Modularity of Resurgent Topological Strings
Abstract: Quantizing the mirror curve of a toric Calabi-Yau threefold gives rise to quantum-mechanical operators. Their fermionic spectral traces produce factorially divergent power series in the Planck constant and its inverse, which are conjecturally captured by the Nekrasov-Shatashvili and standard topological strings via the TS/ST correspondence. In this talk, I will discuss a general conjecture on the resurgence of these dual asymptotic series, and I will present a proven exact solution in the case of the first spectral trace of local P^2. A remarkable number-theoretic structure underpins the resurgent properties of the weak and strong coupling expansions and paves the way for new insights relating them to quantum modular forms. Finally, I will mention how these results fit into a broader paradigm linking resurgence and quantum modularity. This talk is based on arXiv:2212.10606 and further work with V. Fantini (available soon).

Friday 8 March 2024, 10:00 at IPHT, Salle Claude Itzykson, Bât. 774 COURS (Cours) physics
Sylvain Ribault ( IPhT ) Exactly solvable 2D conformal field theories
Abstract: Abstract: In this course, we review two-dimensional CFT in the bootstrap approach, and sketch the known exactly solvable CFTs with no extended chiral symmetry: Liouville theory, (generalized) minimal models, limits thereof, and loop models, including the O(n), Potts and U(n) models. Exact solvability relies on local conformal symmetry, and on the existence of degenerate fields: we explain how these assumptions constrain the spectrum and correlation functions. We discuss the crossing symmetry equations, and how they can be solved analytically or numerically, leading to analytic formulas for structure constants. \\ \\ In the case of loop models, we review the combinatorial description of correlation functions, inspired by the lattice construction of statistical models. We sketch what remains to be done for solving the models. \\ \\ The plan is: \\ 1. The Virasoro algebra and its representations. Fields and operator product expansions.\\ 2. Fusion rules and fusion products. Correlation functions and Ward identities. Crossing symmetry and conformal blocks.\\ 3. Defining a CFT. Diagonal and non-diagonal fields, degenerate fields. Exactly solvable CFTs and their spectrums.\\ 4. Degenerate 4-point functions. Analytic formulas for 2-point and 3-point structure constants.\_ 5. Computing conformal blocks. Numerical bootstrap.\\ 6. Correlation functions in loop models.\\ \\ Livestream on youtube.com/IPhT-TV: no subscription required.\\ Videoconference: subscribe to the course newsletter to receive links

Friday 8 March 2024, 14:00 at LPTHE, library LPTHE-PPH (Particle Physics at LPTHE) hep-ph
Mathieu Pellen ( Freiburg U. ) Theory input for the measurement of W+c production at the LHC
Abstract: The production of W+c at the LHC features very interesting physics but also poses several problems. With the current experimental precision, precise theoretical predictions are therefore crucial to fully explore the physics content of the process. In this presentation, I will present state-of-the-art theoretical predictions and discuss theoretical aspects relevant for the precise measurement of the process.

Monday 11 March 2024, 10:45 at LPTMC, campus Jussieu, couloir 12-13, 5ème étage, salle 5-23 SEM-LPTMC (Séminaire du Laboratoire de Physique Théorique de la Matière Condensée) cond-mat
Paul Robin TBA

Monday 11 March 2024, 13:30 at LPENS, U209 (29 rue d'Ulm) LPENS-MDQ (Séminaire Matériaux et Dispositifs Quantiques du LPENS) cond-mat
Janine Splettstösser ( Chalmers ) Nonthermal resources and fluctuations in nanoscale engines

Tuesday 12 March 2024, 10:30 at IHES, Amphithéâtre Léon Motchane
( Cours de l'IHES )
MATH-IHES (TBA) math
Jonathan Pila ( University of Oxford et IHES ) Point-Counting and the Zilber-Pink Conjecture (4/4)
Abstract: The Zilber-Pink conjecture is a diophantine finiteness conjecture. It unifies and gives a far-reaching generalization of the classical Mordell-Lang and Andre-Oort conjectures, and is wide open in general. Point-counting results for definable sets in o-minimal structures provide a strategy for proving suitable cases which has had some success, in particular in its use in proving the Andre-Oort conjecture. The course will describe the Zilber-Pink conjecture and the point-counting approach to proving cases of it, eventually concentrating on the case of a curve in a power of the modular curve. We will describe the model-theoretic contexts of the conjectures and techniques, and the essential arithmetic ingredients.

Tuesday 12 March 2024, 11:00 at LPTMS, Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530 LPTMS (Séminaire du Laboratoire de Physique Théorique et Modèles Statistiques (Orsay)) cond-mat.stat-mech
Hosho Katsura ( Tokyo University ) TBA

Tuesday 12 March 2024, 11:00 at IHES, Centre de conférences Marilyn et James Simons
( Séminaire Laurent Schwartz )
MATH-IHES (TBA) math
Galina Perelman ( Université Paris-Est - Créteil Val-de-Marne ) On Global Existence for the Derivative Nonlinear Schrödinger Equation on the Torus

Tuesday 12 March 2024, 14:00 at IMO, Online-only. Zoom link by subscribing at https://seedseminar.apps.math.cnrs.fr/ SEED (Seed Seminar of Mathematics and Physics) math-ph
Ngoc Nhi Nguyen ( Università degli Studi di Milano, Italy ) TBA

Tuesday 12 March 2024, 14:00 at IHES, Centre de conférences Marilyn et James Simons
( Cours de l'IHES )
MATH-IHES (TBA) math
Pierre Raphael ( University of Cambridge et IHES ) An Introduction to Super Critical Singularities (1/4)
Abstract: Lecture 1 : Energy super critical singularity formation. Abstract : The description of singularity formation for non linear PDE’s is a classical problem with deep physical roots. Immense progress have been done in the last thirty on the understanding of “bubbling” phenomenon for focusing problems. But recently, new mecanisms have been discovered for “defocusing” problems with a deep connection to fluid mechanics. This series of 4 lectures is intended as a graduate class and will propose an introduction to the key results and open problems in the field, as well as a self contained description of the essential steps of the proofs.

Tuesday 12 March 2024, 14:00 at LPTHE, Library and Zoom (link in the comments) LPTHE-PPH (Particle Physics at LPTHE) hep-ph
Ali Rida Khalifeh ( IAP ) Updated Constraints on Hubble Tension Solutions
Abstract: Since its appearance almost a decade ago, the Hubble Tension received a great deal of proposals to solve it, with none being completely successful. However, new state of the art data improve our assessment of these models and better constrain their parameters. In this talk, which is based on the work in arXiv: 2312.09814, an evaluation of eleven cosmological models is presented. These models consist of five classical extensions of ΛCDM, Early Dark Energy, the Majoron and the varying electron mass models, along with three of the latter’s extensions. This evaluation, previously performed using Planck, ACT and SDSS data (up to DR-12), is now updated with recent SPT-3G, SDSS-DR16 and SH0ES data. Using a set of novel tension metrics, these models are ranked based on which one is able to reduce the tension, and which requires further study before potentially becoming the new concordance model of Cosmology.

Thursday 14 March 2024, 10:00 at IHP, 314 RENC-THEO (Rencontres Théoriciennes) hep-th
António Antunes ( DESY ) The conformal bootstrap reaches higher points
Abstract: The conformal bootstrap is a robust tool for the non-perturbative study of conformal field theories (CFTs) making use unitarity and crossing of simple four-point correlation functions. However, not all observables are accessible in this setup and it is not clear whether a theory can be determined uniquely through these constraints. Higher-point correlation functions of simple operators contain information about an infinite number of four-point correlators with complicated operators, and can potentially address the aforementioned problems. In this talk, I will discuss recent progress in generalizing the bootstrap program to higher-point functions, with emphasis on a positive semi-definite numerical setup for the six-point crossing equation in one dimension. Despite the drastic simplifications with respect to higher dimensions, the problem retains its infinite nature, which we are able to address, obtaining non-trivial bounds on scaling dimensions and four-point functions at fixed kinematics.

seminars from series at institute
in subject with field matching

[ Postscript Poster Aide | PDF Poster Aide | RSS Thread | ICal Format Aide ]

You are invited to subscribe to SEMPARIS mailing lists in order to receive selected announcements by email.

[ Annonces ]    [ Abonnements ]    [ Archive ]    [ Aide ]    [ ]
[ English version ]