5. Theoretical Physics (CSN4)

Searching for Axions in the Lab and in the Cosmo

by Mr Luca Visinelli (Stockholm University &Nordita)

Europe/Rome
Aula Seminari (LNF)

Aula Seminari

LNF

Via Enrico Fermi, 40 00044 Frascati (Roma)
Description
Axions and axion-like particles are excellent dark matter candidates, spanning a vast range of mass scales from the milli- and micro-eV for the QCD axion, to 1E-22 eV for ultralight axions in string theory. In some scenarios, inhomogeneities in the axion density lead to the formation of compact structures known as axion “miniclusters” and axion stars. I will first discuss astrophysical and cosmological constraints on axions at either end of this spectrum, using data from the cosmic microwave background anisotropies and the effects of miniclusters on the gravitational microlensing and on direct detection. I will then assess the formation and the evolution of axion stars in various astrophysical regimes.