Résumé / Abstract Seminaire_GReCO

"Magnetic fields from inflation"

Chiara Caprini
Institut Physique Théorique (IPhT), DSM, CEA-Saclay (Gif-sur-Yvette, France)

Large scale magnetic fields are ubiquitous in the universe: they are observed in galaxies and clusters, even at high redshift, and recently a lower bound on the magnetic field amplitude in the inter-galactic medium has been established using gamma ray telescopes. The origin of cosmological magnetic fields is still unknown, but their presence in the voids among structures points towards a generation in the very early universe. However, there is currently consensus about the absence of a satisfactory model, based on a gauge invariant Lagrangian, able to produce during inflation the magnetic fields present in voids. After reviewing the considerations that lead to such conclusion, I will discuss how it is possible to evade them. I will then proceed to discuss the effect of the magnetic field on metric perturbations.

lundi 30 juin 2014 - 11:00
Salle des séminaires Évry Schatzman,
Institut d'Astrophysique de Paris

Page web du séminaire / Seminar's webpage