Speaker
Daniele Montanino
(Università del Salento & 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 τ. Using the current measurement of τ and the limit on the extra-radiation content ΔNeff by the Planck experiment we put a strong bound on the ALP-photon conversions.
Primary author
Daniele Montanino
(Università del Salento & INFN, Lecce)
Co-authors
Dr.
Alessandro Mirizzi
(Università di Bari & INFN, Bari)
Mr.
Carmelo Evoli
(Laboratori nazionali del Gran Sasso)
Dr.
Matteo Leo
(Durham University - Institute for Particle Physics Phenomenology)