Overview

• In the mirror-sector model, dark quarks and gluons bound by a confining “dark QCD” force form heavy baryons that could collapse into stable, tiny black hole–like objects.
• The cosmic horizon scenario posits a brief accelerated expansion after inflation that gravitationally radiated dark matter particles into existence.
• Each candidate interacts exclusively through gravity, allowing them to evade direct-detection experiments while accounting for roughly 80% of the universe’s mass.
• Profumo proposed the two highly speculative yet calculable frameworks in Physical Review D on May 9 and July 8, 2025.
• These gravity-only models emerge as conventional particle dark matter searches face persistent null results, pointing to new directions for theoretical and observational work.