Two papers in the Physical Review Letters hold that the black holes detected by LIGO may be primordial black holes, and they may explain the nature of dark matter.

Unexpected Explanations

The Laser Interferometer Gravitational-wave Observatory (LIGO) has been one nifty new astronomical tool. In its brief existence, it has been able to detect several of the elusive gravitational waves. Previously, these had just been the stuff of speculations.