The Schwarzschild metric encompasses both exterior and interior regions, with a reversal of signature upon transition from one to the other. Inside the Black Hole, the radial spacelike coordinate transforms into a timelike radius, introducing a time-dependent scale factor on the interior metric's angular term. We investigate situating a Black Hole within another, yielding a spherically symmetric vacuum described by the Schwarzschild metric. As the interior metric's angular term contracts towards the center, the inner Black Hole's surface and gravitational field collapse to a point, ultimately vanishing at the singularity. Homogeneously distributing multiple Black Holes inside the shell allows the interior metric's spacelike t coordinate to characterize the expanding space between them and their gravitational fields. Moreover, we propose a cosmological model wherein the intersection of a Universe and Antiverse spawns FRW Universes, transitioning into Schwarzschild Universes as matter aggregates. This mirrors the Black Hole within a Black Hole scenario, with the FRW Universe acting as the shell's surface. Our model is shown to reconcile with cosmological data, explaining the Universe's Dark Energy without a cosmological constant.
Christopher Laforet (Thu,) studied this question.