https://doi.org/10.1140/epjc/s10052-018-6211-4
Regular Article - Theoretical Physics
gravity models as alternatives to cosmic acceleration
1
Department of Mathematics, Birla Institute of Technology and Science-Pilani, Hyderabad Campus, Hyderabad, 500078, India
2
Departamento de Física, ITA - Instituto Tecnológico de Aeronáutica, São José dos Campos, São Paulo, 12228-900, Brasil
3
Department of Mathematics, Lovely Professional University, Phagwara, Jalandhar, Punjab, 144401, India
* e-mail: pksahoo@hyderabad.bits-pilani.ac.in
Received:
8
May
2018
Accepted:
31
August
2018
Published online:
15
September
2018
This article presents cosmological models that arise in a subclass of 
gravity models, with different f(R) functions and fixed T-dependence. That is, the gravitational lagrangian is considered as , with constant 
. Here R and T represent the Ricci scalar and trace of the stress-energy tensor, respectively. The modified gravitational field equations are obtained through the metric formalism for the Friedmann–Lemaître–Robertson–Walker metric with signature 
. We work with 
, 
and 
, with 
and n all free parameters, which lead to three different cosmological models for our Universe. For the choice of 
, this reduces to widely discussed f(R) gravity models. This manuscript clearly describes the effects of adding the trace of the energy-momentum tensor in the f(R) lagrangian. The exact solution of the modified field equations are obtained under the hybrid expansion law. Also we present the Om diagnostic analysis for the discussed models.
© The Author(s), 2018
