Fast radio bursts from primordial black hole binaries coalescence

In this paper we propose a model in which the coalescence of primordial black hole (PBHs) binaries with equal mass M similar to 10(28) g can emit luminous gigahertz (GHz) radio transient, which may be candidate sources for the observed fast radio bursts (FRBs), if at least one black hole holds an appropriate amount of net electric charge Q. Using a dimensionless quantity for the charge q = Q/root GM, our analyses infer that q similar to O(10(-4.5)) can explain the FRBs with released energy of order O(10(40)) ergs. With the current sample of FRBs and assuming a distribution of charge phi(q) for all PBHs, we can deduce that its form is proportional to q(-3.0 +/- 0.1) for q >= 7.2 x 10(-5) if PBHs are sources of the observed FRBs. Furthermore, with the proposed hypothetical scenario and by estimating the local event rate of FRBs similar to 2.6 x 10(3) Gpc(-3) yr(-1), one derives a lower bound for the fraction of PBHs (at the mass of 10(28) g) against that of matter, f(PBH) (10(28) g) greater than or similar to 10(-5), needed to explain the rate. With this inspiring estimate, we expect that future observations of FRBs can help us to falsify their physical origins from the PBH binaries coalescences. In the future, the gravitational waves produced by mergers of small black holes will be detected by high frequency gravitational wave detectors. We believe that this work will be a useful addition to the current literature on multimessenger astronomy and cosmology.