We propose that the Big Bang was not the origin of all space-time, but a local event within a preexistent geometry: the exterior of an Ultra-Massive Black Hole (UMBH). The UMBH's event horizon is observer-dependent, receding as one falls. The cosmological redshift is reinterpreted as gravitational time dilation from our fall toward the UMBH, yielding the Hubble law. Dark energy emerges as a tidal effect. This model eliminates dark matter and dark energy, unifying cosmology and galactic dynamics. Testable predictions include a correlation between quasar black hole mass and observed time dilation.
Ignacio Fernando Milia (Mon,) studied this question.