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

• Type: Article in International Scientific Journal
• Date: 2008

Authors

bernardini, ae (Author) Other; bertolami, o (Author) Other

Journal

Title: Physical Review D - Particles, Fields, Gravitation and Cosmology

Vol. 77

ISSN: 1550-7998

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 32 Citations

Scopus - 31 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-004-0PP

DOI: 10.1103/physrevd.77.083506

Abstract (EN): 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.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11