Largest temperature of the radiation era and its cosmological implications

By G. Giudice, E. Kolb, A. Riotto. 2000

584 citations recorded by the source corpus.

The thermal history of the universe before the epoch of nucleosynthesis is unknown. The maximum temperature in the radiation-dominated era, which we will refer to as the reheat temperature, may have been as low as 0.7 MeV. In this paper we show that a low reheat temperature has important implications for many topics in cosmology. We show that weakly interacting massive particles (WIMPs) may be produced even if the reheat temperature is much smaller than the freeze-out temperature of the WIMP, and that the dependence of the present abundance on the mass and the annihilation cross section of the WIMP differs drastically from familiar results. We revisit predictions of the relic abundance and resulting model constraints of supersymmetric dark matter, axions, massive neutrinos, and other dark matter candidates, nucleosynthesis constraints on decaying particles, and leptogenesis by decay of superheavy particles. We find that the allowed parameter space of supersymmetric models is altered, removing the usual bounds on the mass spectrum; the cosmological bound on massive neutrinos is drastically changed, ruling out Dirac (Majorana) neutrino masses $m_\nu$ only in the range 33 keV $\simlt m_\nu\simlt$ 6 (5) MeV, which is significantly smaller from the the standard disallowed range 94 eV $\simlt m_\nu\simlt$ 2 GeV (this implies that massive neutrinos may still play the role of either warm or cold dark matter); the cosmological upper bound on the Peccei-Quinn scale may be significantly increased to $ 10^{16}$GeV from the usually cited limit of about $10^{12}$GeV; and that efficient out-of-equilibrium GUT baryogenesis and/or leptogenesis can take place even if the reheat temperature is much smaller than the mass of the decaying superheavy particle.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/9dac242bfd254c685d2b10262aab1a2c49ba381f

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Citations in the corpus

A Review of Gravitational Waves from Cosmic Domain Walls (2017, unknown): “In the case of the perturbative decay of the inflaton, the Hubble parameter at this stage is given by [63]”
Higgs mass and unnatural supersymmetry (2014, background): “Its thermal relic abundance would overclose the universe, so Bino DM requires some source of late entropy injection or low reheat temperature [75, 76].”
Gravitational production of vector dark matter (2020, background): “maximum temperature achieved during the reheating phase can be larger than the temperature at the end of reheating which allows supper-heavy DM production [14].”
Cosmological Moduli and the Post-Inflationary Universe: A Critical Review (2015, background): “12 If there is significant decay of the modulus during the moduli dominated epoch entropy is not conserved and this alters the temperature / scale factor relation [17].”
WIMP dark matter candidates and searches—current status and future prospects (2017, background): “, before the radiation dominated (RD) epoch (for a discussion see [1, 76]).”
Non-Thermal Dark Matter and the Moduli Problem in String Frameworks (2008, background): “The resulting reheat temperature is found to be approximately 32 MeV, which is an acceptable temperature for consistency with the bound of 1 MeV set by BBN [57–60].”
Inflaton oscillations and post-inflationary reheating (2020, background): “When one goes beyond the instantaneous reheating approximation, one finds that if thermalization is sufficiently rapid, the first few decay products begin to heat the Universe to a temperature, Tmax, which could be much larger than TRH [12, 13, 15], though the energy density in the newly created rad”
Freeze-In dark matter with displaced signatures at colliders (2015, methodology): “Freeze-In via scattering during the MDNA era was studied in [6, 7], whereas Freeze-in via decays for goldstino DM was studied in ref.”