Cosmology of strongly interacting fermions in the early universe
arXiv:2104.05271 · doi:10.1088/1475-7516/2021/06/030
Abstract
In view of growing interest in long range scalar forces in the early universe to generate primordial black holes, we study in detail the general relativistic formulation of a Fermi gas interacting with a scalar field in cosmology. Our main finding is that the Yukawa interaction leads to a solution where the scalar field oscillates around zero fermion mass and all energy densities decay as radiation. On one hand, we show that if the Fermi gas starts relativistic, it could stay relativistic. On the other hand, if the fermions are initially non-relativistic, they remain non-relativistic for all practical purposes. We find that in both cases the energy density of the fermions and the scalar field decays as radiation. In the non-relativistic case, this is due to an oscillating and decaying effective mass. Such background dynamics questions whether there is a substantial enhancement of the fermion density fluctuations in the non-relativistic case. Our work can be easily extended to more general field dependent fermion mass. The analysis of the cosmological perturbations will be presented in a follow-up work.
References in corpus (13)
- First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
- Cosmology and the Fate of Dilatation Symmetry
- Primordial Black Holes as Dark Matter: Recent Developments
- Constraints on Earth-mass primordial black holes from OGLE 5-year microlensing events
- No large population of unbound or wide-orbit Jupiter-mass planets
- Growing Matter
- Growing neutrinos and cosmological selection
- Primordial seeds of supermassive black holes
- Constraining the primordial black hole scenario with Bayesian inference and machine learning: the GWTC-2 gravitational wave catalog
- Primordial black holes from long-range scalar forces and scalar radiative cooling
- Dynamics of neutrino lumps in growing neutrino quintessence
- Coupling dark energy with Standard Model states
- Massive Fermi Gas in the Expanding Universe
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- Primordial black holes as a dark matter candidate in theories with supersymmetry and inflation
- Structure Formation after Reheating: Supermassive Primordial Black Holes and Fermi Ball Dark Matter
- Impacts of Jets and Winds From Primordial Black Holes
- Compact objects in and beyond the Standard Model from non-perturbative vacuum scalarization
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- Fireball baryogenesis from early structure formation due to Yukawa forces
- Gravitational waves from rapid structure formation on microscopic scales before matter-radiation equality
- Q-Balls in the presence of attractive force
- Observational Constraints on Early Coupled Quintessence
- Defrosting and Blast Freezing Dark Matter
- Dimming Starlight with Dark Compact Objects
- A Faster Growth of Perturbations in an Early Matter Dominated Epoch: Primordial Black Holes and Gravitational Waves