Simulations of Ellipsoidal PBH Formation and the impact of Non-Spherical effects on the PBH mass function

by Albert Escriva

Thursday 6 Feb 2025, 12:00 → 13:00 Europe/Madrid

IFAE Seminar Room (In-Person)

Numerical simulations have been instrumental in advancing our understanding of primordial black hole (PBH) formation and providing precise estimates of their abundance in the Universe. Traditionally, these simulations have assumed spherical collapse; however, the most realistic initial configuration is an ellipsoid. In this seminar, I will review the current status of PBH formation in the context of the collapse of super-horizon curvature fluctuations, starting with spherically symmetric configurations. Then, I will discuss recent findings on non-spherical PBH formation, focusing on its dynamics and the effect of non-sphericity on the threshold for formation. Our results indicate that, for the cases tested, non-spherical effects are crucial when the fluctuation amplitude is near the collapse threshold (the critical regime), preventing a significant number of configurations from forming black holes. However, when considering these effects in the statistical estimation of the PBH mass function, their overall impact is minimal.