Speaker
Description
In this talk, we propose a novel and natural mechanism of cosmic acceleration driven by primordial black holes (PBHs) with repulsive-like interiors. Using a new ``Swiss Cheese'' cosmological approach we show that this cosmic acceleration is quite general by examining three regular black hole spacetimes, namely the Hayward, the Bardeen and the Dymnikova ones as well as the de Sitter-Schwarzschild, which is singular. In particular, by matching the aforementioned black hole spacetimes with an isotropic and homogeneous expanding Universe, we find a stage of cosmic acceleration that can end either due to black hole evaporation or at an energy scale depending on the parameters of the black hole spacetime considered. Remarkably, we find that ultra-light PBHs with masses $m<5\times 10^8\mathrm{g}$ dominating the energy content of the Univese before Big Bang Nucleosynthesis (BBN) can drive a successful inflationary phase without the use of an inflaton field while PBHs with masses $m \sim 10^{12}\mathrm{g}$ and abundances $0.107 < \Omega^\mathrm{eq}_\mathrm{PBH}< 0.5$ slightly before matter-radiation equality can produce a substantial amount of early dark energy (EDE) relevant for the Hubble tension.
