Ο Τομέας Αστροφυσικής, Αστρονομίας και Μηχανικής σας προσκαλεί στο σεμινάριο της Παρασκευής 05/12/2025 και ώρα 12:00, το οποίο θα διεξαχθεί στο ΑΣΤΕΡΟΣΚΟΠΕΙΟ, στην αίθουσα διαλέξεων «ΒΑΣΙΛΗΣ ΞΑΝΘΟΠΟΥΛΟΣ».
Τίτλος: Primordial black holes as cosmic expansion accelerators
Ομιλητής: Δρ. Κωνσταντίνος Διαλεκτόπουλος, Institute of Space Sciences and Astronomy, University of Malta
Περίληψη:
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 inflation, while PBHs with masses m~10^12 g and abundances 0.107<Ω_PBH^eq<0.5, slightly before matter-radiation equality, can produce a substantial amount of early dark energy, helping to alleviate the Hubble tension.
