In this work an analytic fluid sphere built on the well-known Tolman IV space–time is obtained. This toy model is sourced by an imperfect fluid distribution with a dark matter component. The ...anisotropic behavior is introduced into the system via gravitational decoupling by means of minimal geometric deformation. In this regard, the temporal component of the
θ
-sector has been interpreted as the dark side of the matter distribution. To validate the feasibility of the salient model a detailed graphical analysis is performed, supported by real observational data corresponding to some strange star candidates. Besides, the impacts of minimal geometric deformation approach on the main macro physical observables ı.e, the total mass
M
, compactness factor
u
and surface gravitational red-shift
z
s
are discussed.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In the present article, we have constructed a static charged anisotropic compact star model of Einstein field equations for a spherically symmetric space-time geometry. Specifically, we have extended ...the charged isotropic Heintzmann solution to an anisotropic domain. To address this work, we have employed the gravitational decoupling through the so called minimal geometric deformation approach. The charged anisotropic model is representing the realistic compact objects such as
R
X
J
1856
-
37
and
S
A
X
J
1808.4
-
3658
(
S
S
2
)
. We have reported our results in details for the compact star
R
X
J
1856
-
37
on the ground of physical properties such as pressure, density, velocity of sound, energy conditions, stability conditions, Tolman–Oppenheimer–Volkoff equation and redshift etc.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Durgapal’s fifth isotropic solution describing spherically symmetric and static matter distribution is extended to an anisotropic scenario. To do so we employ the gravitational decoupling through the ...minimal geometric deformation scheme. This approach allows to split Einstein’s field equations in two simply set of equations, one corresponding to the isotropic sector and other to the anisotropic sector described by an extra gravitational source. The isotropic sector is solved by the Durgapal’s model and the anisotropic sector is solved once a suitable election on the minimal geometric deformation is imposes. The obtained model is representing some strange stars candidates and fulfill all the requirements in order to be a well behaved physical solution to the Einstein’s field equations.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this paper we present two new classes of solutions describing compact objects within the framework of five‐dimensional Einstein‐Gauss‐Bonnet (EGB) gravity. We employ the Complete Geometric ...Deformation (CGD) formalism which extends the Minimal Geometric Deformation (MGD) technique adopted in earlier investigations to generate anisotropic models from known isotropic solutions. The two solutions presented arise from mimicking the constraint for the pressure and density respectively which generate independent deformation functions. Rigorous physical tests show that contributions from CDG suppress the effective pressure but enhances the effective density and mass of the compact object, with the suppression/enhancement being modified by the EGB coupling constant. One of the highlights in our findings is that the deformation function along the radial component in CDG is nonzero at the boundary when we mimic both the pressure and density while in MGD we observe a vanishing of this deformation function at the boundary of the fluid configuration only for the pressure constraint. The difference in behavior of the deformation function at the surface predicts different stellar characteristics such as mass‐to‐radius and surface redshifts.
In this paper two new classes of solutions are presented describing compact objects within the framework of five‐dimensional Einstein‐Gauss‐Bonnet (EGB) gravity. The Complete Geometric Deformation (CGD) formalism will be employed which extends the Minimal Geometric Deformation (MGD) technique adopted in earlier investigations to generate anisotropic models from known isotropic solutions. The two solutions presented arise from mimicking the constraint for the pressure and density respectively which generate independent deformation functions. Rigorous physical tests show that contributions from CDG suppress the effective pressure but enhances the effective density and mass of the compact object, with the suppression/enhancement being modified by the EGB coupling constant. One of the highlights in the findings is that the deformation function along the radial component in CDG is nonzero at the boundary when one mimics both the pressure and density while in MGD one observes a vanishing of this deformation function at the boundary of the fluid configuration only for the pressure constraint. The difference in behavior of the deformation function at the surface predicts different stellar characteristics such as mass‐to‐radius and surface redshifts.
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.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This article is devoted to the study of new exact analytical solutions in the background of Reissner–Nordström space-time by using gravitational decoupling via minimal geometric deformation approach. ...To do so, we impose the most general equation of state, relating the components of the
θ
-sector in order to obtain the new material contributions and the decoupler function
f
(
r
). Besides, we obtain the bounds on the free parameters of the extended solution to avoid new singularities. Furthermore, we show the finitude of all thermodynamic parameters of the solution such as the effective density
ρ
~
, radial
p
~
r
and tangential
p
~
t
pressure for different values of parameter
α
and the total electric charge
Q
. Finally, the behavior of some scalar invariants, namely the Ricci
R
and Kretshmann
R
μ
ν
ω
ϵ
R
μ
ν
ω
ϵ
scalars are analyzed. It is also remarkable that, after an appropriate limit, the deformed Schwarzschild black hole solution always can be recovered.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Class I approach as MGD generator Tello-Ortiz, Francisco; Maurya, S. K.; Gomez-Leyton, Y.
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.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this work, we generate curved Lorentzian manifolds from a flat Minkowskian space–time, through the Gravitational Decoupling by the Minimal Geometric Deformation method interpreting the decoupling ...sector as a generator of curvature and matter distribution. In particular, we obtain some new wormhole geometries by imposing either physically relevant equations of state or certain physically–motivated geometric constraints. These solutions are analyzed in detail. For all these solutions, we study the associated energy conditions, the geometric behavior and construct their embedding diagrams.
In this work, we generate curved Lorentzian manifolds from a flat Minkowskian space–time, through the Gravitational Decoupling by the Minimal Geometric Deformation method interpreting the decoupling sector as a generator of curvature and matter distribution. In particular, we obtain some new wormhole geometries by imposing either physically relevant equations of state or certain physically–motivated geometric constraints. These solutions are analyzed in detail. For all these solutions, we study the associated energy conditions, the geometric behavior and construct their embedding diagrams.
Minimally deformed wormholes Tello-Ortiz, Francisco; Maurya, S. K.; Bargueño, Pedro
European physical journal. C, Particles and fields,
05/2021, Letnik:
81, Številka:
5
Journal Article
Recenzirano
Odprti dostop
This work is devoted to the study of wormhole solutions in the framework of gravitational decoupling by means of the minimal geometric deformation scheme. As an example, to analyze how this ...methodology works in this scenario, we have minimally deformed the well-known Morris–Thorne model. The decoupler function
f
(
r
) and the
θ
-sector are determined considering the following approaches: (i) the most general linear equation of state relating the
θ
μ
ν
components is imposed and (ii) the generalized pseudo-isothermal dark matter density profile is mimicked by the temporal component of the
θ
-sector. It is found that the first approach leads to a non-asymptotically flat space-time with an unbounded mass function. To address this issue we have matched both the wormhole and the Schwarzschild vacuum solutions,
via
a thin-shell at the junction surface. Using the second approach, it can be seen that, on one hand, the solution for
γ
=
1
does not give place to a bounded mass and it presents a topological defect at large distances; on the other hand, the wormhole manifold is asymptotically flat in the
γ
=
2
case. In order to satisfy the flare-out condition, we have found restrictions on the value of the
α
parameter, which is related with the amount of exotic matter distribution. Finally, the averaged weak energy condition has been analyzed by using the volume integral quantifier.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this article, new wormhole solutions in the framework of General Relativity are presented. Taking advantage of gravitational decoupling by means of minimal geometric deformation approach and, the ...so–called noncommutative geometry Gaussian and Lorentzian density profiles, the seminal Morris–Thorne space–time is minimally deformed providing new asymptotically wormhole solutions. Constraining the signature of some parameters, the dimensionless constant α is bounded using the flare–out and energy conditions. In both cases, this results in an energy–momentum tensor that violates energy conditions, thus the space–time is threading by an exotic matter distribution. However, it is possible to obtain a positive defined density at the wormhole throat and its neighborhood. To further support the study a thoroughly graphical analysis has been performed.
In this article, new wormhole solutions in the framework of General Relativity are presented. Taking advantage of gravitational decoupling by means of minimal geometric deformation approach and, the so–called noncommutative geometry Gaussian and Lorentzian density profiles, the seminal Morris–Thorne space–time is minimally deformed providing new asymptotically wormhole solutions. Constraining the signature of some parameters, the dimensionless constant α is bounded using the flare–out and energy conditions. In both cases, this results in an energy–momentum tensor that violates energy conditions, thus the space–time is threading by an exotic matter distribution. However, it is possible to obtain a positive defined density at the wormhole throat and its neighborhood. To further support the study a thoroughly graphical analysis has been performed.
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