Naturalness and stability of the generalized Chaplygin gas in the seesaw cosmon scenario

• Type: Article in International Scientific Journal
• Date: 2010

Authors

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

Journal

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

Vol. 81 No. 8

ISSN: 1550-7998

Publisher: American Physical Society

Indexing

ISI Web of Knowledge - 7 Citations

Scopus - 8 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-003-5NE

DOI: 10.1103/physrevd.81.123013

Abstract (EN): The seesaw mechanism is conceived on the basis that a mass scale, xi, and a dimensionless scale, s, can be fine-tuned in order to control the dynamics of active and sterile neutrinos through cosmon-type equations of motion: the seesaw cosmon equations. This allows for sterile neutrinos to be a dark matter candidate. In this scenario, the dynamical masses and energy densities of active and sterile neutrinos can be consistently embedded into the generalized Chaplygin gas (GCG), the unified dark sector model. In addition, dark matter adiabatically coupled to dark energy allows for a natural decoupling of the (active) mass varying neutrino component from the dark sector. Thus mass varying neutrinos turn into a secondary effect. Through the scale parameters, xi and s, the proposed scenario allows for a convergence among three distinct frameworks: the cosmon scenario, the seesaw mechanism for mass generation, and the GCG model. It is found that the equation of state of the perturbations is the very one of the GCG background cosmology so that all the results from this approach are maintained, being smoothly modified by active neutrinos. Constrained by the seesaw relations, it is shown that the mass varying mechanism is responsible for the stability against linear perturbations and is indirectly related to the late time cosmological acceleration.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 11