Magnetic fields in the early Universe

18.01.2019 11:30 – 12:30

Magnetic fields are an ubiquitous presence in our Universe but a comprehensive theory describing their generation and evolution is still missing. A broadly accepted paradigm wants these fields to be generated by the amplification of pre-existing weaker fields during the gravitational collapse accompanying structure formation. However the mechanisms behind the generation of these seeds are yet to be understood. An intriguing possibility is that these seed fields are generated in the pre-recombination Universe and then evolve passively until the epoch of structure formation. A clean way to prove the presence of primordial magnetic fields (PMF) is to look at Cosmic Microwave Background (CMB) anisotropies induced by these fields. In this talk, I will discuss the behavior of magnetic fields in the pre-recombination epoch and their imprints on the CMB spectra. I will review the current bounds coming from the combination of various CMB probes such as the Planck satellite and the South Pole Telescope. Furthermore I will also show what we expect to learn in the future from next generation CMB experiments. Finally I will discuss how magnetic fields evolves in the post-recombination regime and their impact on structure formation.

Lieu

Bâtiment: Ecole de Physique

Salle 234, 24 quai Ernest-Ansermet

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