In this work we have extended the Maurya-Gupta isotropic fluid solution to Einstein field equations to an aniso-tropic domain. To do so, we have employed the gravitational decoupling via the minimal ...geometric deformation approach. The present model is representing the strange star candidate LMC X-4. A mathematical, physical and graphical analysis, shown that the obtained model fulfills all the criteria to be an admissible solution of the Einstein field equations. Specifically, we have analyzed the regularity of the metric potentials and the effective density, radial and tangential pressures within the object, causality condition, energy conditions, equilibrium via Tolman–Oppenheimer–Volkoff equation and the stability of the model by means of the adiabatic index and the square of subliminal sound speeds.
In the present article, we have obtained a new solution for the charged compact star model through the gravitational decoupling (GD) by using a complete geometric deformation (CGD) approach (Ovalle, ...Phys Lett B 788:213, 2019). In this approach, the initial decoupled system is separated into two subsystems namely Einstein–Maxwell’s system and quasi-Einstein system. We solve Einstein–Maxwell’s system by taking well known Tolman–Kuchowicz spacetime geometry in the context of the perfect fluid matter distribution. On the other hand, the second system introduce the anisotropy inside the matter distribution which is solved by taking an EOS in
θ
components. The boundary conditions have been derived to determine the constants parameter. To support the mathematical and physical analysis of the present GD solution, we have plotted all the graphs for the compact objects PSR J1614-2230, 4U1608-52 and Cen X-3 corresponding to the constant
α
=
0.001
, 0.0012 and 0.0014, respectively. Moreover, we also studied the equilibrium and stability of the solution. The present study shows that the GD technique is a very significant tool to generalize the solution in a more complex form or one matter distribution to another matter distribution.
In this article, we have investigated a new completely deformed embedding class one solution for the compact star in the framework of charged anisotropic matter distribution. For determining of this ...new solution, we deformed both gravitational potentials as
ν
↦
ξ
+
α
h
(
r
)
and
e
-
λ
↦
e
-
μ
+
α
f
(
r
)
by using Ovalle (Phys Lett B 788:213, 2019) approach. The gravitational deformation divides the original coupled system into two individual systems which are called the Einstein’s system and Maxwell-system (known as quasi-Einstein system), respectively. The Einstein’s system is solved by using embedding class one condition in the context of anisotropic matter distribution while the solution of Maxwell-system is determined by solving of corresponding conservation equation via assuming a well-defined ansatz for deformation function
h
(
r
). In this way, we obtain the expression for the electric field and another deformation function
f
(
r
). Moreover, we also discussed the physical validity of the solution for the coupled system by performing several physical tests. This investigation shows that the gravitational decoupling approach is a powerful methodology to generate a well-behaved solution for the compact object.
In the present paper, we discuss the role of gravitational decoupling to isotropize the anisotropic solution of Einstein’s field equations in the context of the complete geometric deformation (CGD) ...approach and its influence on the complexity factor introduced by Herrera (Phys Rev D 97:044010, 2018) in the static self-gravitating system. Moreover, we proposed a simple and effective technique as well to generate new solutions for self-gravitating objects via CGD approach by using two systems with the same complexity factor and vanishing complexity factor proposed by Casadio et al. (Eur Phys J C 79:826, 2019). The effect of decoupling constant and the compactness on the complexity factor have also been analyzed for the obtained solutions.
We obtain a new anisotropic solution for spherically symmetric spacetimes by analyzing the Karmarkar embedding condition. For this purpose we construct a suitable form of one of the gravitational ...potentials to obtain a closed form solution. This form of the remaining gravitational potential allows us to solve the embedding equation and integrate the field equations. The resulting new anisotropic solution is well behaved, which can be utilized to construct realistic static fluid spheres. Also we estimated the masses and radii of fluid spheres for LMC X-4, EXO 1785-248, PSR J1903+327 and 4U 1820-30 by using observational data set values. The masses and radii obtained show that our anisotropic solution can represent fluid spheres to a very good degree of accuracy. The physical validity of the solution depends on the parameter values of
a
,
b
and
c
. The solution is well behaved for the wide range of parameters values
0.00393
≤
a
≤
0.0055
,
0.0002
≤
b
≤
0.0025
and
0.0107
≤
c
≤
0.0155
. The range of corresponding physical parameters for the different compact stars are
0.3266
≤
v
r
0
≤
0.3708
,
0.1583
≤
v
t
0
≤
0.2558
,
0.3256
≤
z
s
≤
0.4450
and
4.3587
≤
Γ
0
≤
5.6462
.
Class I approach as MGD generator Tello-Ortiz, Francisco; Maurya, S. K.; Gomez-Leyton, Y.
The European physical journal. C, Particles and fields,
04/2020, Letnik:
80, Številka:
4
Journal Article
Recenzirano
Odprti dostop
In this work we build a relativistic anisotropic admissible compact structures. To do so we combine the class I approach with gravitational decoupling in order to generate the deformation function
f
...(
r
). As an example we have re-anisotropized two anisotropic matter distributions previously obtained by the class I procedure. To produce all the graphical study supporting this analysis, we have considered the data corresponding to the compact object 4U 1538-52, SMC X-1 and LMC X-4 for model 1 and Cen X-3 for model 2. In considering the last one, we have taken the constant parameter
α
to be
{
-
0.3
;
0.1
;
0.3
}
. It is found that the resulting models satisfy all the general requirement in order to represent or describe realistic compact structures such as neutron or quark stars.
In this article, we have presented a static anisotropic solution of stellar compact objects for self-gravitating system by using minimal geometric deformation techniques in the framework of embedding ...class one space-time. For solving of this coupling system, we deform this system into two separate system through the geometric deformation of radial components for the source function
λ
(
r
)
by mapping:
e
-
λ
(
r
)
→
e
-
λ
~
(
r
)
+
β
g
(
r
)
, where
g
(
r
) is deformation function. The first system corresponds to Einstein’s system which is solved by taking a particular generalized form for source function
λ
~
(
r
)
while another system is solved by choosing well-behaved deformation function
g
(
r
). To test the physical viability of this solution, we find complete thermodynamical observable as pressure, density, velocity, and equilibrium condition via. TOV equation etc. In addition to the above, we have also obtained the moment of inertia (
I
), Kepler frequency (
v
), compression modulus (
K
e
) and stability for this coupling system. The
M
–
R
curve has been presented for obtaining the maximum mass and corresponding radius of the compact objects.
Utilizing an ansatz developed by Maurya et al. we present a class of exact solutions of the Einstein–Maxwell field equations describing a spherically symmetric compact object. A detailed physical ...analysis of these solutions in terms of stability, compactness and regularity indicates that these solutions may be used to model strange star candidates. In particular, we model the strange star candidate Her X-1 and show that our solution conforms to observational data to an excellent degree of accuracy. An interesting and novel phenomenon which arises in this model is the fact that the relative difference between the electromagnetic force and the force due to the pressure anisotropy changing sign within the stellar interior. This may be an additional mechanism required for stability against cracking of the stellar object.
In this work, we present a new class of analytic and well-behaved solution to Einstein’s field equations describing anisotropic matter distribution. It’s achieved in the embedding class one spacetime ...framework using Karmarkar’s condition. We perform our analysis by proposing a new metric potential
g
rr
which yields us a physically viable performance of all physical variables. The obtained model is representing the physical features of the solution in detail, analytically as well as graphically for strange star candidate SAX J1808.4-3658 (
M
a
s
s
=
0.9
M
⊙
,
r
a
d
i
u
s
=
7.951
km), with different values of parameter
n
ranging from 0.5 to 3.4. Our suggested solution is free from physical and geometric singularities, satisfies causality condition, Abreu’s criterion and relativistic adiabatic index
Γ
, and exhibits well-behaved nature, as well as, all energy conditions and equilibrium condition are well-defined, which implies that our model is physically acceptable. The physical sensitivity of the moment of inertia (
I
) obtained from the solutions is confirmed by the Bejger−Haensel concept, which could provide a precise tool to the matching rigidity of the state equation due to different values of
n
viz.,
n
=
0.5
,
1.08
,
1.66
,
2.24
,
2.82
and 3.4.