Exact barotropic distributions in Einstein-Gauss-Bonnet gravity

Maharaj, S. D.; Chilambwe, Brian; Hansraj, Sudan

doi:10.1103/physrevd.91.084049

Cited by 79 publications

(46 citation statements)

References 32 publications

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“…Recently exact interior metrics were reported [1][2][3] for spherically symmetric perfect fluid distributions in the EinsteinGauss-Bonnet (EGB) gravity theory. The exterior metric was derived by Boulware and Deser [4] for neutral spheres and by Wiltshire [5] for the charged counterpart a few decades ago.…”

Section: Introductionmentioning

confidence: 99%

Generalized spheroidal spacetimes in 5-D Einstein–Maxwell–Gauss–Bonnet gravity

Hansraj

2017

Eur. Phys. J. C

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The field equations for static EGBM gravity are obtained and transformed to an equivalent form through a coordinate redefinition. A form for one of the metric potentials that generalizes the spheroidal ansatz of Vaidya-Tikekar superdense stars and additionally prescribing the electric field intensity yields viable solutions. Some special cases of the general solution are considered and analogous classes in the Einstein framework are studied. In particular the FinchSkea ansatz is examined in detail and found to satisfy the elementary physical requirements. These include positivity of pressure and density, the existence of a pressure free hypersurface marking the boundary, continuity with the exterior metric, a subluminal sound speed as well as the energy conditions. Moreover, the solution possesses no coordinate singularities. It is found that the impact of the Gauss-Bonnet term is to correct undesirable features in the pressure profile and sound speed index when compared to the equivalent Einstein gravity model. Furthermore graphical analyses suggest that higher densities are achievable for the same radial values when compared to the 5-dimensional Einstein case. The case of a constant gravitational potential, isothermal distribution as well as an incompressible fluid are studied. All exact solutions derived exhibit an equation of state explicitly.

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Section: Introductionmentioning

confidence: 99%

Generalized spheroidal spacetimes in 5-D Einstein–Maxwell–Gauss–Bonnet gravity

Hansraj

2017

Eur. Phys. J. C

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“…For more examples, we may note that the HEE equation in f (R) and f (G) gravities werediscussed in (Astashenok 2015b;Momeni 2015b;Astashenok 2015a;Abbas 2015), d-dimensional HEE in EN gravity was investigated in (Ponce 2000) and HEE of EN-Λ gravity with arbitrary dimensions was obtained in (Bordbar 2015). In addition, 5 and higher dimensional HEE in context of Gauss-Bonnet (GB) gravity was extracted in (Zhan-Ying 2012;Hansraj 2015;Bordbar 2015). Recently, (2 + 1)-dimensional HEE was obtained for a static star in the presence of cosmological constant (Diaz 2014).…”

Section: Introductionmentioning

confidence: 99%

Dilatonic equation of hydrostatic equilibrium and neutron star structure

Hendi

Bordbar

Panah

et al. 2015

Astrophys Space Sci

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In this paper, we present a new hydrostatic equilibrium equation related to dilaton gravity. We consider a spherical symmetric metric to obtain the hydrostatic equilibrium equation of stars in 4-dimensions, and generalize TOV equation to the case of regarding a dilaton field. Then, we calculate the structure properties of neutron star using our obtained hydrostatic equilibrium equation employing the modern equations of state of neutron star matter derived from microscopic calculations. We show that the maximum mass of neutron star depends on the parameters of dilaton field and cosmological constant. In other words, by setting the parameters of new hydrostatic equilibrium equation, we calculate the maximum mass of neutron star.

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“…The only difference with the expression given in [4] is the factor (n − 3) in the last term of Eqn (13). This second order equation has two singular regular points in u = ±1 and we can write the solution around u = 0 as in: [4] …”

Section: Metric and Einstein Equationsmentioning

confidence: 99%

“…There is also fairly large literature on star interior solution in higher dimensions, we give some representative references [7][8][9][10][11][12][13]. We have here studied how 4-dimensional solution could be taken over to appropriate higher dimensions in BVT metric ansatz.…”

Section: Introductionmentioning

confidence: 99%

Higher dimensional generalization of the Buchdahl-Vaidya-Tikekar model for a supercompact star

2016

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We obtain higher dimensional solutions for super compact star for the BuchdahlVaidya-Tikekar metric ansatz. In particular, Vaidya and Tikekar characterized the 3-geometry by a parameter, K which is related to the sign of density gradient. It turns out that the key pressure isotropy equation continues to have the same Gauss form, and hence 4-dimensional solutions can be taken over to higher dimensions with K satisfying the relation, K n = (K 4 − n + 4)/(n − 3) where subscript refers to dimension of spacetime. Further K ≥ 0 is required else density would have undesirable feature of increasing with radius, and the equality indicates a constant density star described by the Schwarzschild interior solution. This means for a given K 4 , maximum dimension could only be n = K 4 + 4, else K n will turn negative.

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Exact barotropic distributions in Einstein-Gauss-Bonnet gravity

Cited by 79 publications

References 32 publications

Generalized spheroidal spacetimes in 5-D Einstein–Maxwell–Gauss–Bonnet gravity

Generalized spheroidal spacetimes in 5-D Einstein–Maxwell–Gauss–Bonnet gravity

Dilatonic equation of hydrostatic equilibrium and neutron star structure

Higher dimensional generalization of the Buchdahl-Vaidya-Tikekar model for a supercompact star

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