Filtered cogenesis of PBH dark matter and baryons

TL;DR

This paper introduces a new mechanism for generating both dark matter and baryons through a first-order phase transition in the dark sector, leading to primordial black holes and dark asymmetry transfer, with potential observational signatures in gravitational waves.

Contribution

It presents a novel filtered cogenesis model where phase transition dynamics produce PBHs as dark matter and transfer asymmetry to the visible sector, linking dark matter, baryogenesis, and gravitational wave signals.

Findings

Primordial black holes can form from false vacuum collapse, constituting dark matter.

Dark asymmetry can transfer to the visible sector via bubble wall decay.

Model predicts stochastic gravitational wave signals detectable by future experiments.

Abstract

We propose a novel cogenesis of baryon and dark matter (DM) in the Universe by utilising a first-order phase transition (FOPT) in the dark sector containing an asymmetric Dirac fermion $\chi$. Due to the mass difference of $\chi$ across the bubble walls, it is energetically favourable for $\chi$ to get trapped in the false vacuum leading to the formation of Fermi-ball, which can self-collapse to form primordial black hole (PBH) if $\chi$ has a sufficiently large Yukawa interaction. While such PBH formed out of false vacuum collapse can give rise to the DM in the Universe, a tiny amount of asymmetric $\chi$ leaking into the true vacuum through the bubble walls can transfer the dark asymmetry into the visible sector via decay. The same mass difference of $\chi$ across the two minima which decides the amount of trapping or filtering of $\chi$, also allows $\chi$ decay into visible sector in the true minima while keeping it stable in the false vacuum. Our filtered cogenesis scenario can be probed via FOPT generated stochastic gravitational waves (GW) at near future detectors in addition to the well-known detection aspects of asteroid mass PBH constituting DM in the Universe.