The Dark Universe as a Quantum-Gravitational Phase: Eliminating Singularities and Particle Dark Matter in One Framework

The Dark Universe as a Quantum-Gravitational Phase: Eliminating Singularities and Particle Dark Matter in One Framework The Dark Universe as a Quantum-Gravitational Phase: Eliminating Singularities and Particle Dark Matter in One Framework We propose an alternative to particulate dark matter: a saturated, non-local phase of spacetime that emerges at a quantum-gravitational density limit. From the Generalized Uncertainty Principle (GUP) with gravitational corrections, we derive a mass-dependent upper bound on density, ρ_max(M) = 6c⁶/(πG³M²), which implies a minimum stable radius r_min = r_s/4 for any mass M. Applying this bound to the total baryonic mass of the observable universe, we find that this mass, compressed to ρ_max, would occupy only ≈ 0.6% of the observable universe's volume. This geometric framework offers a unified approach to three longstanding problems: (1) it replaces black hole singularities with a phase transition into a dark substrate; (2) it provides a non-particulate candidate origin for dark matter; (3) it establishes a phenomenological bridge to quantum gravity. The model yields a testable, falsifiable prediction: damped gravitational-wave echoes following intermediate-mass binary black hole mergers (remnant mass ≈ 340–1400 M⊙), in the 50–200 Hz band, with characteristic amplitude decay proportional to t^{-5/6}, which could be constrained by LIGO/Virgo/KAGRA observations. This is a preprint version of the manuscript. The work has been submitted for peer review and is shared here to solicit community feedback and discussion. All comments and questions are welcome.