RECONSTRUCTION OF f(R, T) GRAVITY DESCRIBING MATTER DOMINATED AND ACCELERATED PHASES

Abstract

We investigate the cosmological reconstruction in modified f (R, T ) gravity, where R is the Ricci scalar and T the trace of the stress-energy tensor. Special attention is attached to the case in which the function f is given by f (R, T ) = f1(R) + f2(T ). The use of auxiliary scalar field is considered with two known examples for the scale factor corresponding to an expanding universe. In the first example, where ordinary matter is usually neglected for obtaining the unification of matter dominated and accelerated phases with f (R)gravity, it is shown in this paper that this unification can be obtained without neglect ordinary matter. In the second example, as in f (R)gravity, model of f (R, T ) gravity with transition of matter dominated phase to the acceleration phase is obtained. In both cases, linear function of the trace is assumed for f2(T ) and it is obtained that f1(R) is proportional to a power of R with exponents depending on the input parameters.Pacs numbers: 98.80.-k, 95.36.+x, 11.25.-w

Reconstructing QCD ghost f(R,T) models

“…In this respect the search of most appropriate form of Lagrangian is still under consideration. f (R, T ) theory of gravity has been reconstructed under various scenarios including de Sitter, power law solutions, phantom, nonphantom eras, anisotropic universe model and class of HDE models (Houndjo 2012;Zubair 2013c, 2014a). In this work, we reconstruct f (R, T ) gravity corresponding to Garcia-Salcedo and modified QCD ghost DE models.…”

“…Here, f (T ) is a correction to the usual Einstein Hilbert action. Such model appears to be interesting and has been widely studied in literature (Houndjo 2012;Zubair 2013c, 2014a). The corresponding field equations are…”

“…In this study, one interesting way is to consider the known cosmic evolution and use the field equations to find particular form of Lagrangian that can reproduce the given evolution background. The cosmological reconstruction has been investigated in the framework of f (R, T ) gravity realizing the ΛCDM, phantom, non-phantom eras and unification of matter dominated and accelerated phases (Houndjo 2012;Zubair 2013c, 2014a). In this paper, we are interested to develop an equivalence between f (R, T ) gravity and GDE without utilizing any additional DE component.…”

Cosmological viable f(R,T) dark energy model: dynamics and stability

“…The dependence on T may be a consequence of the universe being partially filled by an exotic imperfect fluid, or consequence of quantum effects coming from conformal anomaly. Several works have been developed in the framework of this kind of modified theory of gravity and considerable results have been found [5]- [17]. However, anywhere, these theories took into account the important aspect of guaranteeing the conservation of the energy momentum tensor.…”

Searching for a cosmological preferred axis in complicated class of cosmological models: case study f (R, T ) model

“…[33] introduced this type of the Modified Gravity, f (R, T ), which obtained significant outcomes: the reconstruction of cosmological solutions, where late-time acceleration was accomplished by [34] and the energy conditions was analyzed by [3]. [52] studied the thermodynamics of FriedmannLemaître-Robertson-Walker (FLRW) spacetimes.…”