Primordial regular black holes (part 1)

I would be lying if I didn’t say I am particularly proud of this new paper which appeared today with Marco Calzà and Davide Pedrotti, making it another made in Trentino paper and, especially, another paper entirely produced within my group (note that this paper is for 2/3 made within the Valle dei Laghi, which is where both Marco and Davide originally come from)! There are a huge number of studies on primordial black holes (PBHs) as potential dark matter (DM) candidates, yet virtually (almost) all of these works consider Schwarzschild or Kerr BHs, which suffer from a few well-known problems, including the presence of curvature singularities. In today’s paper we therefore took a first step towards characterizing primordial regular BHs (which, on the contrary, do not feature curvature singularities) as DM candidates, finding that they can potentially lead to a larger “asteroid mass window” where PBHs can make up all the DM. Today’s pilot study is focused on so-called tr-symmetric metrics, which include the well-known Bardeen and Hayward regular BHs, whereas we have also put out a companion paper (covered in this other news item), where we study non-tr-symmetric metrics, which also include metrics inspired from Loop Quantum Gravity. You can read our results in the preprint we just posted on arXiv: 2409.02804.