Primordial black holes as a dark matter candidate in theories with supersymmetry and inflation

Abstract

We show that supersymmetry and inflation, in a broad class of models, generically lead to formation of primordial black holes (PBHs) that can account for dark matter. Supersymmetry predicts a number of scalar fields that develop a coherent condensate along the flat directions of the potential at the end of inflation. The subsequent evolution of the condensate involves perturbative decay, as well as fragmentation into Q-balls, which can interact by some long-range forces mediated by the scalar fields. The attractive scalar long-range interactions between Q-balls facilitates the growth of Q-balls until their ultimate collapse to black holes. For a flat direction lifted by supersymmetry breaking at the scale $\Lambda\sim 100$ TeV, the black hole masses are of the order of $(M_{\rm Planck}^3/\Lambda^2)\sim 10^{22}$ g, in the allowed range for dark matter. Similar potentials with a lower scale $\Lambda$ (not necessarily associated with supersymmetry) can result in a population of primordial black holes with larger masses, which can explain some recently reported microlensing events.