Anisotropic compact objects in f(T) gravity with Finch–Skea geometry

Chanda, A.; Dey, Sagar; Paul, Bikash Chandra

doi:10.1140/epjc/s10052-019-7020-0

Cited by 54 publications

(33 citation statements)

References 52 publications

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“…The approach can be summarized as follows: we used a non-diagonal form of the tetrad field that gives a null value of the torsion as soon as the metric potentials approach to 1. This is a necessary condition for any physical tetrad field as reported in various studies [93,[131][132][133][134][135][136][137].…”

Section: Discussionmentioning

confidence: 99%

Stable and self-consistent compact star models in teleparallel gravity

Nashed

Capozziello

2020

Eur. Phys. J. C

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In the framework of Teleparallel Gravity, we derive a charged non-vacuum solution for a physically symmetric tetrad field with two unknown functions of radial coordinate. The field equations result in a closed-form adopting particular metric potentials and a suitable anisotropy function combined with the charge. Under these circumstances, it is possible to obtain a set of configurations compatible with observed pulsars. Specifically, boundary conditions for the interior spacetime are applied to the exterior Reissner–Nordström metric to constrain the radial pressure that has to vanish through the boundary. Starting from these considerations, we are able to fix the model parameters. The pulsar $$\textit{PSR J 1614-2230}$$ PSR J 1614 - 2230 , with estimated mass $$M= 1.97 \pm 0.04\, M_{\circledcirc },$$ M = 1.97 ± 0.04 M ⊚ , and radius $$R= 9.69 \pm 0.2$$ R = 9.69 ± 0.2 km is used to test numerically the model. The stability is studied, through the causality conditions and adiabatic index, adopting the Tolman–Oppenheimer–Volkov equation. The mass–radius (M, R) relation is derived. Furthermore, the compatibility of the model with other observed pulsars is also studied. We reasonably conclude that the model can represent realistic compact objects.

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Section: Discussionmentioning

confidence: 99%

Stable and self-consistent compact star models in teleparallel gravity

Nashed

Capozziello

2020

Eur. Phys. J. C

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“…It is interesting to point out, the nonlinear equation of state ( 46) contains the modified Chaplygin equation of state which has been extensively utilize in different studies. For instance, in the case of charged anisotropic fluid spheres [76][77][78][79] and in the framework of f (T ) gravity theory [80,81]. The Chaplygin modified equation of state has proven to be adaptable tools to investigate many open problems at the theoretical level.…”

Section: Equation Of Statementioning

confidence: 99%

Relativistic compact stars in Tolman spacetime via an anisotropic approach

Bhar¹,

Rej²,

Takisa

et al. 2021

Eur. Phys. J. C

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In this present work, we have obtained a singularity-free spherically symmetric stellar model with anisotropic pressure in the background of Einstein’s general theory of relativity. The Einstein’s field equations have been solved by exploiting Tolman ansatz [Richard C Tolman, Phys. Rev. 55:364, 1939] in $$(3+1)$$ ( 3 + 1 ) -dimensional space-time. Using observed values of mass and radius of the compact star PSR J1903+327, we have calculated the numerical values of all the constants from the boundary conditions. All the physical characteristics of the proposed model have been discussed both analytically and graphically. The new exact solution satisfies all the physical criteria for a realistic compact star. The matter variables are regular and well behaved throughout the stellar structure. Constraints on model parameters have been obtained. All the energy conditions are verified with the help of graphical representation. The stability condition of the present model has been described through different testings.

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“…To summarize, in the present paper we have used a nondiagonal form of tetrad field that gives null values of the off-diagonal components of the field equations unlike what has been studied in the literature [82][83][84][85][86][87][88]. We show that solution (18) depends on the tangential EoS which is not familiar for compact star and solution (20) has infinite central pressure as shown in Fig.…”

Section: Discussionmentioning

confidence: 83%

Neutral physical compact spherically symmetric stars with non-exotic matters in Einstein’s cluster model using Weitzenböck geometry

2020

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We revisit the neutral (uncharged) solutions that describe Einstein’s clusters with matters in the frame of Weitzenböck geometry. To this end, we use a tetrad field with non-diagonal spherical symmetry which gives vanishing of the off-diagonal components of the gravitational field equations. The cluster solutions are calculated by using an anisotropic energy–momentum tensor. We solve the field equations using two novel assumptions. First, we use an equation of state that relates density with tangential pressure, and then we assume a specific form of one of the metric potentials in addition to the assumption of the vanishing of radial pressure to make the system of differential equations in a closed-form. The resulting solutions are coincide with the literature $$ however \, \,in\, \,this\, \,study\, \,we\, \,constrain\,\, the\,\, constants \, \,of\, \, integration\, \, from\, \, \,the\, \, matching\,\, of\, \,boundary $$ h o w e v e r i n t h i s s t u d y w e c o n s t r a i n t h e c o n s t a n t s o f i n t e g r a t i o n f r o m t h e m a t c h i n g o f b o u n d a r y $$ condition\, \, in a\,\, way \,\,different\,\, from\,\, that\,\, presented \,\,in \,\,the\,\, literature. $$ c o n d i t i o n i n a w a y d i f f e r e n t f r o m t h a t p r e s e n t e d i n t h e l i t e r a t u r e . Among many things presented in this study, we investigate the static stability specification and show that our model is consistent with a real compact start except that the tangential pressure has a vanishing value at the center of the star which is not accepted from the physical viewpoint of a real compact star. We conclude that the model that has vanishing radial pressure in the frame of Einstein’s theory is not a physical model. Therefore, we extend this study and derive a new compact star without assuming the vanishing of the redial pressure but instead we assume new form of the metric potentials. We repeat our procedure done in the case of vanishing radial pressure and show in details that the new compact star is more realistic from different physical viewpoints of real compact stellar.

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Anisotropic compact objects in f(T) gravity with Finch–Skea geometry

Cited by 54 publications

References 52 publications

Stable and self-consistent compact star models in teleparallel gravity

Stable and self-consistent compact star models in teleparallel gravity

Relativistic compact stars in Tolman spacetime via an anisotropic approach

Neutral physical compact spherically symmetric stars with non-exotic matters in Einstein’s cluster model using Weitzenböck geometry

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