Cosmology in scalartensor f (R , T ) gravity
Abstract
In this work, we use reconstruction methods to obtain cosmological solutions in the recently developed scalartensor representation of f (R ,T ) gravity. Assuming that matter is described by an isotropic perfect fluid and the spacetime is homogeneous and isotropic, i.e., the FriedmannLemaîtreRobertsonWalker (FLRW) universe, the energy density, the pressure, and the scalar field associated with the arbitrary dependency of the action in T can be written generally as functions of the scale factor. We then select three particular forms of the scale factor: an exponential expansion with a (t )∝e^{t} (motivated by the de Sitter solution); and two types of powerlaw expansion with a (t )∝t^{1 /2} and a (t )∝t^{2 /3} (motivated by the behaviors of radiation and matterdominated universes in general relativity, respectively). A complete analysis for different curvature parameters k ={1 ,0 ,1 } and equation of state parameters w ={1 ,0 ,1 /3 } is provided. Finally, the explicit forms of the functions f (R ,T ) associated with the scalarfield potentials of the representation used are deduced.
 Publication:

Physical Review D
 Pub Date:
 March 2022
 DOI:
 10.1103/PhysRevD.105.064019
 arXiv:
 arXiv:2112.02541
 Bibcode:
 2022PhRvD.105f4019G
 Keywords:

 General Relativity and Quantum Cosmology
 EPrint:
 14 pages, 18 figures