Modified Brans–Dicke cosmology with matter-scalar field interaction. (29th June 2016)

• Record Type: Journal Article
• Authors: Kofinas, Georgios; Papantonopoulos, Eleftherios; Saridakis, Emmanuel N
• Is Part Of: Classical and quantum gravity. Volume 33:Number 15(2016:Aug.)
• Publication Date: 2016-06-29
• Subjects: modified gravities -- cosmology -- late-times acceleration; Quantum gravity -- Periodicals; Gravitation -- Periodicals; Relativity (Physics) -- Periodicals; Space and time -- Periodicals; Periodicals; 521.1
• DOI: 10.1088/0264-9381/33/15/155004
• Languages: English
• ISSNs: 0264-9381

Abstract

Abstract: We discuss the cosmological implications of an extended Brans–Dicke theory presented recently, in which there is an energy exchange between the scalar field and ordinary matter, determined by the theory. A new mass scale is generated in the theory which modifies the Friedmann equations with field-dependent corrected kinetic terms. In a radiation Universe the general solutions are found and there are branches with complete removal of the initial singularity, while at the same time a transient accelerating period can occur within deceleration. Entropy production is also possible in the early Universe. In the dust era, late-times acceleration has been found numerically in agreement with the correct behavior of the density parameters and the dark energy equation of state, while the gravitational constant has only a slight variation over a large redshift interval in agreement with observational bounds.