Baryon asymmetry from primordial black holes

Abstract

We propose a new scenario of the baryogenesis from primordial black holes (PBH). Assuming presence of a microscopic baryon (or lepton) number violation and a CP violating operator such as \(\partial_\alpha F(\mathcal{R_{....}} ) J^\alpha\) where \(F(\mathcal{R_{....}})\) is a scalar function of the Riemann tensor, time evolution of an evaporating black hole generates baryonic (leptonic) chemical potential at the horizon; consequently PBH enumerates asymmetric Hawking radiation between baryons (leptons) and anti-baryons (leptons). Though the operator is higher dimensional and largely suppressed by a high mass scale \(M_*\), we show that sufficient amount of asymmetry can be generated for wide range of parameters of the PBH mass \(M_{\rm PBH}\), its abundance \(\Omega_{\rm PBH}\), and the scale \(M_*\).