Not quite black holes as dark matter

Understand

Primordial black holes that survive until the present have been considered as a dark matter candidate.

• In this paper we argue that primordial 2-2-hole remnants provide a more promising and testable option.
• 2-2-holes arise in quadratic gravity as a new family of classical solutions for ultracompact matter distributions and they possess the black hole exterior without an event horizon.
• They may serve as the endpoint of gravitational collapse, providing a resolution for the information loss problem.