Existence of compact structures in f(R, T) gravity
Eur. Phys. J. C
Existence of compact structures in f ( R, T ) gravity
Z. Yousaf 1
M. Zaeem-ul-Haq Bhatti 0 1
M. Ilyas 0
0 Centre for High Energy Physics, University of the Punjab , Quaid-i-Azam Campus, Lahore 54590 , Pakistan
1 Department of Mathematics, University of the Punjab , Quaid-i-Azam Campus, Lahore 54590 , Pakistan
The present paper is devoted to investigate the possible emergence of relativistic compact stellar objects through modified f ( R, T ) gravity. For anisotropic matter distribution, we used Krori and Barura solutions and two notable and viable f ( R, T ) gravity formulations. By choosing particular observational data, we determine the values of constant in solutions for three relativistic compact star candidates. We have presented some physical behavior of these relativistic compact stellar objects and some aspects like energy density, radial as well as transverse pressure, their evolution, stability, Eos parameters, measure of anisotropy and energy conditions.
1 Introduction
General relativity (GR) is considered as the most fruitful
theory for understanding the evolution of universe and its
hidden secrets, yet the evidence of dark matter (DM) and
the cosmic accelerating nature of spacetime put some
challenges on this [
1–15
]. The Einstein’s GR explained the
cosmological phenomena in a regime of weak field, while some
modifications may be needed to study the strong fields in the
scenario of accelerating expansion of the universe. In this
direction, Qadir et al. [
16
] reinforced the requirement of the
modified relativistic dynamics and indicated that this
modification may help to settle down the problems related to DM
and quantum gravity. As a result, many techniques were used
like by introducing the cosmological constant as well as the
modified theories from time to time.
Modified gravitational theories (MGTs) are actually the
generalization of GR in which function of the Ricci scalar
( R) is substituted in the Einstein–Hilbert action. These
modified gravity theories are dubbed with the names,
Einstein[
17
], f ( R) [
18–21
] ( R is the Ricci scalar), f ( R, T ) [
22–25
]
(T is the trace of energy momentum tensor), f (G) [
26
] (G is
the Gauss–Bonnet term) and f ( R, T , Rξ π T ξ π ) gravity [
27–
30
]. In the recent times, Nojiri et al. [31] presented various
mathematical techniques to understand burning issues of
cosmos related to bouncing cosmos. They asserted that gravity
mediated by f ( R) and f (G) theories could be used to
realize many hidden secrets of our universe. Once can observe
the pity good agreement results between the cosmological
models in MGTs and the observational data [
32–35
]. The
f ( R, T ) gravity is one of the MGTs, in which the f ( R) is
replaced with the function of R and T [36]. It is claimed that
the evidence behind the dependence of T may come from
the presence of imperfect fluid or it may be some kinds of
quantum effects (for further reviews on DE and MGTs, see,
for instance, [
37–51
]).
In f ( R, T ) gravity, many cosmological applications were
discussed in [
52–58
]. From literature, some of them are, The
non-static line element for collapsing of spherical body
having anisotropic fluid were discussed in [
59
]. The static
spherical wormhole solutions were found in [
60, 61
]. Furthermore,
the perturbation techniques were used in study of
spherical stars [62]. The effects on gravitational lensing due to
f ( R, T ) gravity were discussed in [
63
]. The spherical
equilibrium theme of polytropic and strange stars were
investigated in [
64
]. Houndjo [
65
] constructed few observationally
notable cosmic models in f ( R, T ) gravity for studying
matter dominated era of the expanding universe. Baffou et al.
[
66
] applied perturbation on the spacetimes of de-Sitter and
power law models in order to explore some cosmic viability
bounds.
Bamba et al. [
67
] analyzed the effects of higher degrees of
freedom coming from MGT on the dynamical features of our
accelerating cosmos. Bamba et al. [
73
] further checked the
viability regimes on the parameters of f (G) gravity
models and presented some mathematically consistent cosmic
zones. The stability of gravitational evolving stellar bodies
have been investigated in few models of f (R) gravity by
[
69,71
]. Das et al. [72] calculated exact relativistic models of
spherical interiors in MGT and discussed the physical
implications of their results on compact stars.
Yousaf and his collaborators examined the role of
various curvature invariant functions on the existence as well
as stability of the planar [
74–76
], spherical [
17,77–80
] and
cylindrical [
23,81–83
] geometries. Sahoo with his
coworkers [
84–86
] studied the viability of the spatially regular
cosmos along with some other cosmological aspects in f (R, T )
gravity. Moraes et al. [64] worked out the stability of some
well-known compact stars by computing their corresponding
hydrostatic equations in f (R, T (...truncated)