Perturbative approach for mass varying neutrinos coupled to the dark sector in the generalized Chaplygin gas scenario

Journal Article · Tue Apr 15 04:00:00 EDT 2008 · Physical Review. D, Particles Fields

DOI:https://doi.org/10.1103/PHYSREVD.77.083506· OSTI ID:21250001

Bernardini, A E; Bertolami, O ^[1]

---

1. Instituto Superior Tecnico, Departamento de Fisica, Av. Rovisco Pais, 1, 1049-001, Lisboa (Portugal)

We suggest a perturbative approach for generic choices for the universe equation of state and introduce a novel framework for studying mass varying neutrinos (MaVaN's) coupled to the dark sector. For concreteness, we examine the coupling between neutrinos and the underlying scalar field associated with the generalized Chaplygin gas (GCG), a unification model for dark energy and dark matter. It is shown that the application of a perturbative approach to MaVaN mechanisms translates into a constraint on the coefficient of a linear perturbation, which depends on the ratio between a neutrino energy dependent term and scalar field potential terms. We quantify the effects on the MaVaN sector by considering neutrino masses generated by the seesaw mechanism. After setting the GCG parameters in agreement with general cosmological constraints, we find that the squared speed of sound in the neutrino-scalar GCG fluid is naturally positive. In this scenario, the model stability depends on previously set up parameters associated with the equation of state of the universe. Our results suggest that the GCG is a particularly suitable candidate for constructing a stable MaVaN scenario.

• OSTI ID: 21250001
• Journal Information: Physical Review. D, Particles Fields, Journal Name: Physical Review. D, Particles Fields Journal Issue: 8 Vol. 77; ISSN PRVDAQ; ISSN 0556-2821
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
COUPLING
DISTURBANCES
ENERGY DEPENDENCE
EQUATIONS OF STATE
FLUIDS
MASS
NEUTRINOS
NONLUMINOUS MATTER
PERTURBATION THEORY
SCALAR FIELDS
SOUND WAVES
UNIVERSE
VELOCITY