Primordial Asymmetries, Primordial Equation of State & Primordial Black Holes
Abstract
We study the thermal history of the primordial Universe in the presence of non-zero lepton and baryon asymmetries. Considering different scenarios, we determine the equation of state (EoS) of the Universe from T = 10 GeV down to T = 1 keV, spanning the QCD transition, hadron gas phase and neutrino decoupling epochs. Using a combination of numerical codes, we track the cosmic trajectories of chemical potentials associated with the baryonic, leptonic and electric charges, and follow the evolution of lepton asymmetries including through the era where neutrino oscillations take place. Combining peak theory with numerical-relativity simulations of the collapse threshold, we show the EoS-induced modifications to the primordial black hole (PBH) mass spectrum. We determine the associated Gravitational Wave (GW) signal, showing how lepton asymmetries and a particular spectral index of curvature perturbations can be hinted at by current ground interferometer-based GW observations. Finally, we discuss constraints and positive evidence for PBHs.
Related
- Search for subsolar primordial black holes in low mass-ratio binaries with LIGO-Virgo O2 data and implications for the primordial black hole dark matter fraction
- Theory-constrained hierarchical inference of primordial black holes in f(Q, T) gravity with GWTC-3
- Gravitational wave signals from primordial black holes orbiting solar-type stars
- All Dark Matter as Primordial Black Holes: a Gravitational-Wave Test
- Small-Scale Clustering of Primordial Black Holes: The Little Red Dot Mass Function and the High-Redshift Galaxy Tension
BibTeX
@misc{gonin2026primordial,
title = {{Primordial Asymmetries, Primordial Equation of State & Primordial Black Holes}},
author = {Maël Gonin and Julien Froustey and Albert Escrivà and Alberto Magaraggia and Günther Hasinger and Florian Kühnel},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2608.22240},
eprint = {2608.22240},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2608.22240},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Primordial Asymmetries, Primordial Equation of State & Primordial Black Holes
AU - Maël Gonin
AU - Julien Froustey
AU - Albert Escrivà
AU - Alberto Magaraggia
AU - Günther Hasinger
AU - Florian Kühnel
PY - 2026
DA - 2026/09/09
PB - arXiv
DO - 10.48550/arxiv.2608.22240
UR - https://arxiv.org/abs/2608.22240
AB - We study the thermal history of the primordial Universe in the presence of non-zero lepton and baryon asymmetries. Considering different scenarios, we determine the equation of state (EoS) of the Universe from T = 10 GeV down to T = 1 keV, spanning the QCD transition, hadron gas phase and neutrino decoupling epochs. Using a combination of numerical codes, we track the cosmic trajectories of chemical potentials associated with the baryonic, leptonic and electric charges, and follow the evolution of lepton asymmetries including through the era where neutrino oscillations take place. Combining peak theory with numerical-relativity simulations of the collapse threshold, we show the EoS-induced modifications to the primordial black hole (PBH) mass spectrum. We determine the associated Gravitational Wave (GW) signal, showing how lepton asymmetries and a particular spectral index of curvature perturbations can be hinted at by current ground interferometer-based GW observations. Finally, we discuss constraints and positive evidence for PBHs.
ER -