How the Big Bang Ends up Inside a Black Hole

TL;DR

This paper proposes a novel cosmological model where the universe originates from a gravitational collapse and bounce inside a black hole, potentially explaining cosmic expansion without inflation or dark energy.

Contribution

It introduces the BH Universe (BHU) model, suggesting the universe's origin from a black hole collapse and bounce, challenging standard cosmological assumptions.

Findings

Collapse generates a black hole of ~5×10^{22} solar masses.

Bounce produces the Big Bang expansion without inflation.

Perturbations exit and re-enter the horizon, explaining cosmic structure.

Abstract

The standard model of cosmology assumes that our Universe began 14 Gyrs (billion years) ago from a singular Big Bang creation. This can explain a vast range of different astrophysical data from a handful of free cosmological parameters. However, we have no direct evidence or fundamental understanding of some key assumptions: Inflation, Dark Matter and Dark Energy. Here we review the idea that cosmic expansion originates instead from gravitational collapse and bounce. The collapse generates a Black Hole (BH) of mass $ M \simeq 5 \times 10^{22} M_{\odot}$ that formed 25~Gyrs ago. As there is no pressure support, the cold collapse can continue inside in free fall until it reaches atomic nuclear saturation (GeV), when is halted by Quantum Mechanics, as two particles cannot occupy the same quantum state. The collapse then bounces like a core-collapse supernovae, producing the Big Bang expansion. Cosmic acceleration results from the BH event horizon. During collapse, perturbations exit the horizon to re-enter during expansion, giving rise to the observed universe without the need for Inflation or Dark Energy. Using Ockham's razor, this makes the BH Universe (BHU) model more compelling than the standard singular Big Bang creation.