Berry phases, wormholes and factorization in AdS/CFT [Remote talk]

Within the AdS/CFT correspondence, the entanglement properties of the CFT are related to wormholes in the dual gravity theory. This gives rise to questions about the factorisation properties of the Hilbert spaces on both sides of the correspondence.  We review these issues and show how the Berry phase, a geometrical phase encoding information about topology, […]

[Journal Club] Right-handed neutrinos, TeV scale BSM neutral Higgs boson, and FIMP dark matter in an EFT framework

Abstract: We consider an effective field theory framework with three Standard Model (SM) gauge singlet right-handed neutrinos and an additional SM gauge singlet scalar field. The framework generates eV masses of light neutrinos via the seesaw mechanism and accommodates a feebly interacting massive particle (FIMP) as a dark matter candidate. Two of the gauge singlet […]

CMB, LSS and the distance ladder: cosmic discordance? [Remote talk]

The Lambda-cold-dark-matter (LCDM) model has established itself as a fantastic (yet parametric)  concordance model able to adjust a wide variety of cosmological observables — CMB, BBN, Large Scale Structure (LSS) & SN1a most notably.  However as the precision of the data has increased over the past few years, a number of predictions of the LCDM […]

The Tadpole Problem [Remote talk]

I will discuss string theory compactifications where a large number of moduli is stabilized by fluxes. I will first present a conjecture which rules out the stabilization of all complex-structure moduli in F-theory at a generic point in moduli space by fluxes that satisfy the tadpole cancellation condition. Evidence for this conjecture comes from studying K3xK3 compactifications using […]

AnLy Strings & Fields 2nd in-person Meeting

This is a meeting on topics related to string and field theory, between members of nearby institutions: IP2I (CNRS, UCBL), Lyon LAPTh (CNRS, USMB), Annecy LPENSL (CNRS, ENSL), Lyon More information can be found on the AnLy webpage. For this second edition, the meeting will take place in IP2I, Lyon, on the 19/05/22. Talks will […]

Three-dimensional flux vacua from Type II supergravities

We discuss flux compactifications of Type IIA supergravity on G2 spaces with smeared O2/O6-planes down to three dimensions. We start by presenting the setup of allowed fluxes, the internal geometry, the equations of motion and after compactification we achieve N=1 AdS3 vacua with scale that can be parametrically decoupled from the KK modes. The solutions […]

Imprints of axion-like particles in photon spectra from galaxy clusters

Modulations of X-ray spectra from extragalactic sources might provide a signature of photons converting into axion-like particles (ALPs) when traversing a region with a large-scale magnetic field. A crucial unknown in these searches is the structure of the magnetic field considered. In this talk I discuss the impact of realistic models of the magnetic field on […]

Higgs alignment and the top quark

In 1976, S. Weinberg and his student, E. Gildener (GW), proposed multi-Higgs models of electroweak symmetry breaking which are clas- sically scale-invariant. If this scale invariance is spontaneously broken, the Higgs boson is the resulting massless dilaton and, of all the model’s scalars, its couplings to gauge bosons and fermions are exactly as in the […]

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. […]