Pierre Fest

Participation to the event is by invitation only. If you would like to participate or contribute in some way, please contact serpico _at_ lapth.cnrs.fr. Unless LAPTh administration takes care of your trip, please think of reserving transportation and (above all!) the hotel ASAP, since Annecy is a tourist destination at all times of the year. […]

Dynamique et chaos dans les systèmes planétaires [Colloquium]

L'organisation du Système Solaire et la description des mouvements qui le caractérisent ont constitué le cœur de l'astronomie pendant de siècles depuis l'antiquité. Cette science appelée Mécanique Céleste qui repose sur la théorie de la gravitation a connu son heure de gloire au XIXe siècle, avant de passer au second plan devant l'essor de l'astrophysique. […]

[Journal Club] Feynman integrals for precision high-multiplicity scattering

Abstract: We review recent advances in the calculation of the two-loop Feynman integrals which contribute to five-particle scattering amplitudes with one massive leg. These amplitudes are required to provide theoretical predictions for the three-particle production (two massless and one massive particle) at the next-to-next-to leading-order approximation. We will compare several analytic approaches to the problem […]

Alphabets for Quantum Field Theory

As the LHC accumulates data, the need grows for more efficient methods to compute scattering amplitudes. One such method manages to swap the difficult problem of integrating thousands of Feynman diagrams for a much simpler one: solving a system of linear equations. This can be done when there is a known "alphabet" of appropriate singularities […]

Non-deformation quantisation of integrable systems

We will present a new approach to the problem of quantising integrable systems of differential-difference equations. The main idea is to lift these systems to systems defined on free associative algebras and look for the ideals there  that are stabilized by the dynamics of the lifted systems. In a reasonable class of candidate ideals, there […]

Self-Organised Localisation

 I will describe a new phenomenon in quantum cosmology: self-organised localisation. When the fundamental parameters of a theory are functions of a scalar field subject to large fluctuations during inflation, quantum phase transitions can act as dynamical attractors. As a result, the theory parameters are probabilistically localised around the critical value and the Universe finds […]

[Journal Club] Muon g-2 and lepton flavor violation

Abstract:  Vector-Like Leptons and Inert Scalar Triplet: Lepton Flavor Violation, $g-2$ and Collider Searches (arxiv.org)   Zoom link: https://cnrs.zoom.us/j/91049381574?pwd=TDZyU3NqT0k4MFk3cUMvc0JuOURCdz09

Entanglement entropy of free fermions on graphs

Abstract: The von Neumann entropy is key quantity in quantum information and in the investigation of many-body models. In this talk, we will show that tools from algebraic combinatorics and […]