Thermal relics in cosmology with bulk viscosity

Abstract

In this paper we discuss some consequences of cosmological models in which the primordial cosmic matter is described by a relativistic imperfect fluid. The latter takes into account the dissipative effects (bulk viscosity) arising from different cooling rates of the fluid components in the expanding Universe. We discuss, in particular, the effects of the bulk viscosity on Big Bang Nucleosynthesis and on the thermal relic abundance of particles, looking at recent results of PAMELA experiment. The latter has determined an anomalous excess of positron events, that cannot be explained by the conventional cosmology and particle physics.

10 pages

References in corpus (19)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• A Theory of Dark Matter
• Leptogenesis
• Measurement of the Cosmic Ray e+ plus e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope
• A new measurement of the antiproton-to-proton flux ratio up to 100 GeV in the cosmic radiation
• The origin of the positron excess in cosmic rays
• The new form of the equation of state for dark energy fluid and accelerating universe
• Constraints on WIMP Dark Matter from the High Energy PAMELA $\bar{p}/p$ data
• Bulk Viscous Cosmology
• High-energy antiprotons from old supernova remnants
• Can a matter-dominated model with constant bulk viscosity drive the accelerated expansion of the universe?
• Bulk Viscosity, Decaying Dark Matter, and the Cosmic Acceleration
• Observational implications of mattergenesis during inflation
• Constraining pre Big-Bang-Nucleosynthesis Expansion using Cosmic Antiprotons
• Bulk viscosity of a gas of neutrinos and coupled scalar particles, in the era of recombination
• Enlarging mSUGRA parameter space by decreasing pre-BBN Hubble rate in Scalar-Tensor Cosmologies
• Inhomogeneous viscous dark fluid coupled with dark matter in the FRW universe
• Cosmological perturbations in warm-tachyon inflationary universe model with viscous pressure
• Warm-Intermediate Inflationary Universe Model with Viscous Pressure in High Dissipative Regime

Cited by in corpus (1)

• Constraints on Tsallis Cosmology from Big Bang Nucleosynthesis and the Relic Abundance of Cold Dark Matter Particles