Baryon asymmetry from primordial black holes

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