Isotropic compact stars model in Rastall theory admitting conformal motion

Abbas, G.; Shahzad, M. R.

doi:10.1007/s10509-018-3472-1

Cited by 52 publications

(10 citation statements)

References 41 publications

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“…In addition, they showed that by applying Visser's approach to f (R) theory one may conclude that it is equivalent to GR as well which is not true. Different studies have proven that RT is not equivalent to GR [88][89][90][91]. Visser's conclusion is correct when Ricci scalar vanishes for black holes in general, otherwise the claim is incorrect and both theories are not equivalent.…”

Section: Introductionmentioning

confidence: 96%

Non-trivial class of anisotropic compact stellar model in Rastall gravity

Nashed

Hanafy

2022

Eur. Phys. J. C

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We investigated Rastall gravity, for an anisotropic star with a static spherical symmetry, whereas the matter-geometry coupling as assumed in Rastall Theory (RT) is expected to play a crucial role differentiating RT from General Relativity (GR). Indeed, all the obtained results confirm that RT is not equivalent to GR, however, it produces same amount of anisotropy as GR for static spherically symmetric stellar models. We used the observational constraints on the mass and the radius of the pulsar Her X-1 to determine the model parameters confirming the physical viability of the model. We found that the matter-geometry coupling in RT allows slightly less size than GR for a given mass. We confirmed the model viability via other twenty pulsars’ observations. Utilizing the strong energy condition we determined an upper bound on compactness $$U_\text {max}\sim 0.603$$ U max ∼ 0.603 , in agreement with Buchdahl limit, whereas Rastall parameter $$\epsilon =-0.1$$ ϵ = - 0.1 . For a surface density compatible with a neutron core at nuclear saturation density the mass-radius curve allows masses up to $$3.53 M_\odot $$ 3.53 M ⊙ . We note that there is no equation of state is assumed, however the model fits well with linear behaviour. We split the twenty pulsars into four groups according to the boundary densities. Three groups are compatible with neutron cores while one group fits perfectly with higher boundary density $$8\times 10^{14}$$ 8 × 10 14 $$\hbox {g/cm}^3$$ g/cm 3 which suggests that those pulsars may have quark-gluon cores.

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Section: Introductionmentioning

confidence: 96%

Non-trivial class of anisotropic compact stellar model in Rastall gravity

Nashed

Hanafy

2022

Eur. Phys. J. C

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“…In this respect, the well known Tolman solutions have been extended into the Rastall gravity arena [49] in order to contrast the behavior of the main salient features with the corresponding GR ones. Furthermore, to reinforce the study of stellar interiors in the Rastall scenario an anisotropic model in the background of Krori-Barua (KB) space-time was done in [50] (in [51] the same authors considered KB space-time supplemented by an equation of state, specifically a quintessence model) and an isotropic compact object using conformal Killing vector technique was reported in [52]. Regarding the strong gravitational regime, remarkable solutions of black holes were presented in [53,54].…”

Section: Introductionmentioning

confidence: 99%

Decoupling gravitational sources by MGD approach in Rastall gravity

Maurya

Tello‐Ortiz

2020

Physics of the Dark Universe

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In the present work, we investigate the possibility of obtaining stellar interiors for static selfgravitating systems describing an anisotropic matter distribution in the framework of Rastall gravity through gravitational decoupling by means of minimal geometric deformation approach. Due to Rastall gravity breaks down the minimal coupling matter principle, we have provided an exhaustive explanation about how Israel-Darmois junction conditions work in this scenario. Furthermore, to obtain the deformed space-time, the mimic constraint procedure has been used. In order to check the viability of this proposal, we have applied it to the well known Tolman IV solution. A complete thermodynamic description of the effects introduced by the additional source is given. Additionally, the results have been compared with their similes in the picture of pure general relativity, pure Rastall gravity and within the framework of general relativity including gravitational decoupling. To perform the mathematical and graphical analysis we have taken the gravitational decoupling constant α and the Rastall's parameter λ as free parameters and the compactness factor u to be 0.2. Applications to study neutron or quark stars are suggested by using this methodology.

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“…In recent years, the theory of gravity proposed by Peter Rastall [38], has gained growing interest, with studies of the implications of this theory in the context of black holes [39][40][41][42][43], thermodynamic of black holes [44][45][46], wormholes [47,48], for cosmological scenarios [49][50][51][52] as well as some proposals of generalizations of the Rastall's gravity [53,54] and of combining this theory with others modifications of GR [9,55,56] and in particular in the study of compact objects [7,9,[57][58][59][60][61][62], but we still lack a study of the effects of Rastall's theory on rotating stars. So, in this work, we will consider these elements in order to formulate a model for rotating stars in the Rastall theory.…”

Section: Introductionmentioning

confidence: 99%

Rapidly rotating compact stars in Rastall's gravity

da Silva,

Santos,

Barros

2020

Preprint

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Isotropic compact stars model in Rastall theory admitting conformal motion

Cited by 52 publications

References 41 publications

Non-trivial class of anisotropic compact stellar model in Rastall gravity

Non-trivial class of anisotropic compact stellar model in Rastall gravity

Decoupling gravitational sources by MGD approach in Rastall gravity

Rapidly rotating compact stars in Rastall's gravity

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