Speaker
Dr
Daniele Montanino
(Universita del Salento and INFN, Lecce)
Description
Recently it has been pointed out that a cosmic background of
relativistic axion-like particles (ALPs) would be produced
by the primordial decays of heavy fields(moduli) in the
post-inflation epoch, contributing to the extra-radiation
content in the Universe today. Primordial magnetic fields
would trigger conversions of these ALPs into sub-MeV photons
during the dark ages. This photon flux would produce an
early reionization of the Universe, leaving a significant
imprint on the total optical depth to recombination ?. Using
the current measurement of ? and the limit on the
extra-radiation content ?Neff by the Planck experiment we
put a strong bound on the ALP-photon conversions.
Primary author
Dr
Daniele Montanino
(Universita del Salento and INFN, Lecce)
