Primordial black holes from scalar field evolution in the early universe

摘要

Scalar condensates with large expectation values can form in the early universe, for example, in theorieswith supersymmetry. The condensate can undergo fragmentation into Q-balls before decaying. If theQ-balls dominate the energy density for some period of time, statistical fluctuations in their number densitycan lead to formation of primordial black holes (PBH). In the case of supersymmetry the mass range islimited from above by 1023 g. For a general charged scalar field, this robust mechanism can generate blackholes over a much broader mass range, including the black holes with masses of 1–100 solar masses, whichis relevant for LIGO observations of gravitational waves. Topological defects can lead to formation of PBHin a similar fashion.