Jun 19 – 21, 2023
Naples, Italy
Europe/Rome timezone

Axion-like particles from light primordial black holes

Jun 21, 2023, 5:00 PM
20m
Naples, Italy

Naples, Italy

Talk Session 12

Speaker

Mr Daniele Montanino (Università del Salento & INFN)

Description

We consider a cosmological scenario in which the very early Universe experienced a transient epoch of matter domination due to the formation of a large population of primordial black holes (PBHs) with masses $M \leq 10^9~{\rm g}$, that evaporate before Big Bang nucleosynthesis. In this context, Hawking radiation would be a non-thermal mechanism to produce a cosmic background of axion-like particles (ALPs). We assume the minimal scenario in which these ALPs couple only with photons. In the case of ultralight ALPs ($m_a \leq 10^{-9}~{\rm eV}$) the cosmic magnetic fields might trigger ALP-photon conversions, while for masses m a ≳ 10 eV spontaneous ALP decay in photon pairs would be effective. We investigate the impact of these mechanisms on the cosmic X-ray background, on the excess in X-ray luminosity in Galaxy Clusters, and on the process of cosmic reionization. We outline possible developments of this scenario including BH rotation and superradiance.

Primary author

Mr Daniele Montanino (Università del Salento & INFN)

Presentation materials