Primordial black holes from supercooled first-order phase transition

 Cosmological first-order phase transition are said strongly supercooled when the nucleation temperature is much smaller than the critical temperature. They are typical of  potentials which feature nearly scale-invariance, for which the bounce action decreases only logarithmically with time. The phase transition takes place slowly and the probability distribution of bubble nucleation time is maximally spread. […]

[Journal Club] A novel theoretical approach to $R(D^{(*)})$ through the Dispersive Matrix method

Abstract: The ratios $R(D^{(*)})$ are defined as the $tau/mu$ ratio of the branching fractions of exclusive semileptonic $B to D^{(*)}$ decays. They are a powerful test of Lepton Flavour Universality, one of the pillars of the SM, and are determined by the hadronic Form Factors (FFs) describing the $B to D^{(*)}$ decays. Through the novel Dispersive Matrix (DM) approach, […]

Intelligent Explorations of the String Theory Landscape [Remote talk]

The goal of identifying the Standard Model of particle physics and its extensions within string theory has been one of the principal driving forces in string phenomenology. Recently, the incorporation of artificial intelligence in string theory and certain theoretical advancements have brought to light unexpected solutions to mathematical hurdles that have so far hindered progress […]

[Journal Club] Bootstrapping Pions at Large N

Abstract: For this journal club meeting I will comment on a recent paper by Albert and Rastelli (https://arxiv.org/abs/2203.11950) in which they apply modern S-matrix bootstrap techniques to the old problem of solving QCD in the large N limit. In particular, they derive universal bounds for the EFT of massless pions and find that the allowed […]

Star forming galaxies as cosmic ray factories: a multimessenger view

Star forming galaxies (SFGs) are powerful factories of high-energy cosmic rays. Their star formation rate (SFR) is a key physical property characterizing both the total energy budget and the transport conditions of such particle populations. Tight correlations are in fact observed between the SFR and the non-thermal radio and gamma-ray luminosity of several SFGs. I […]

RAQIS 22

Recent Advances in Quantum Integrable Systems

Newtonian regime in a spherical or hyperbolic universe and consequences for the role of spatial curvature in cosmology

The standard model of cosmology currently allows for three types of geometries for our Universe (Euclidean, spherical or hyperbolic), each of these types corresponding to a set of different (multiconnected)-topologies. Among these geometries, Newton’s theory of gravity is only defined on the Euclidean one. Still, extending the validity of this theory to the two other […]

Alpine Strings 2022

This 1-day workshop aims at gathering in Annecy the local string and quantum field theory community for fruitful exchanges on active research topics. Those include: Bootstrap   Swampland program and string phenomenology Supergravity and Exceptional Field Theories Participating institutions are mainly LPENS (Lyon), IP2I (Lyon), LAPTh (Annecy), CERN (Meyrin), UNIGE (Geneva) and EPFL (Lausanne). Young […]

News from the Universe: A Trio of Intriguing Developments in Astrophysics and Cosmology

Auditorium (LAPTh)

Speakers: Christopher Eckner (CNRS, LAPTh) Abstract:I will present three recent papers advancing our understanding of astrophysics and cosmology. The covered papers are:I)  arXiv:2304.0607: "The Image of the M87 Black Hole Reconstructed with PRIMO"   A crisper image of the supermassive black hole of M87 with machine learningII)  arXiv:2304.09895: "Anomalies in Gravitational-Lensed Images Revealing Einstein Rings Modulated by […]