Could tiny black hole leftovers be all the dark matter?

Loop quantum gravity predicts that evaporating black holes leave behind stable Planck-mass remnants rather than disappearing entirely. Mapping out which primordial black hole masses are compatible with this idea, the authors find a sweet spot near 1,000 kg: these objects evaporate via Hawking radiation to reheat the Universe, leave remnants that make up all of today's dark matter, and require no fine-tuning of their initial abundance. The scenario produces gravitational wave signals detectable by LIGO, the Einstein Telescope, and LISA.