APEC Seminar (Astronomy - Particle Physics - Experimental Physics - Cosmology)

Speaker: Kenichi Saikawa (Max-Planck-Institute)
Title: Axion dark matter mass: Towards a reliable estimate
Date: Wed, Aug 21, 2019, 13:30 - 14:30
Place: Seminar Room A
Abstract: Axions are well-motivated hypothetical particles as they arise as a solution to the strong CP problem of QCD and are regarded as a good candidate for cold dark matter. In light of recent developments of experimental approaches on the search for axion dark matter, it is important to clarify what is the typical theoretical prediction for its mass. The prediction for the axion dark matter mass can be obtained by fixing its relic abundance, which is however not straightforward to estimate since we must take account of the contribution of axions radiated from global strings if the Pecceci-Quinn symmetry is restored and broken after inflation. In this talk, we review the issue of the production mechanism of dark matter axions and present new results of ongoing large scale numerical simulations on the cosmological evolution of global strings.