About a (standard model) universe dominated by the right matter

Abstract

We analyze the phenomenology of a prolonged early epoch of matter domination by an unstable but very long-lived massive particle. This new matter domination era can help to relax some of the requirements on the primordial inflation. Its main effect is the huge entropy production produced by the decays of such particle that can dilute any possible unwanted relic, as the gravitino in supersymmetric models, and thus relax the constraints on the inflationary reheating temperature. Furthermore, a long period of matter domination reduces the number of $e$-foldings after the horizon crossing by observable perturbations and therefore the requirements on flatness of the inflationary potential. A natural candidate for such heavy, long-lived particle already present in the Standard Model of the electroweak interactions would be a heavy right-handed neutrino. In this case, we show that its decays can also generate the observed baryon asymmetry with right-handed neutrino masses well above the bound from gravitino overproduction.

14 pages, 3 figures. References on late time enthropy release included, several points clarified

References in corpus (20)

• The Cosmological Parameters 2006
• Big-Bang nucleosynthesis (Particle Data Group mini-review)
• Leptogenesis
• Big-Bang Nucleosynthesis and Hadronic Decay of Long-Lived Massive Particles
• Recent Progress in Baryogenesis
• Leptogenesis as the origin of matter
• Thermal Inflation and the Moduli Problem
• Cosmological Constraints on Late-time Entropy Production
• Cosmology with a TeV mass GUT Higgs
• Constraints on the Reheating Temperature in Gravitino Dark Matter Scenarios
• Inflation models and observation
• Unified origin of baryons and dark matter
• Spontaneous CP violation and Non-Abelian Family Symmetry in SUSY
• Seesaw and Lepton Flavour Violation in SUSY SO(10)
• SO(10) theory of R-parity and neutrino mass
• Production and dilution of gravitinos by modulus decay
• Intermediate Scales in Supersymmetric GUTs: the Survival of the Fittest
• A SUSY SO(10) GUT with an Intermediate Scale
• Late-Time Entropy Production and Relic Abundances of Neutralinos
• Right-handed neutrinos as the source of density perturbations

Cited by in corpus (4)

• Unified origin of baryons and dark matter
• The Baryon-Dark Matter Ratio Via Moduli Decay After Affleck-Dine Baryogenesis
• Inflation might be caused by the right
• The Compactification Problems of Additional Dimensions in Multidimensional Cosmological Theories