29 June 2026 to 3 July 2026
Physicum, University of Tartu
Europe/Tallinn timezone

Primordial Black Holes as cosmic expansion accelerators

29 Jun 2026, 11:25
25m
A106 (Physicum, University of Tartu)

A106

Physicum, University of Tartu

W. Ostwaldi 1, Tartu

Speaker

Dr Konstantinos Dialektopoulos (University of Malta)

Description

In this seminar, I will present a novel mechanism for cosmic acceleration driven by primordial black holes with effective repulsive behavior. Using a new Swiss Cheese cosmological framework, I will discuss four black hole spacetimes—Hayward, Bardeen, Dymnikova, and de Sitter-Schwarzschild—to show that this acceleration emerges naturally from the geometry itself. The results suggest that ultra-light PBHs could drive inflation without requiring an inflaton, 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, helping to alleviate the Hubble tension.

Author

Dr Konstantinos Dialektopoulos (University of Malta)

Presentation materials