Stable and ‘bounded excursion’ gravastars, and black holes in Einstein’s theory of gravity

Rocha, P.; Chan, R.; Silva, M.F.A. da; Wang, Anzhong

doi:10.1088/1475-7516/2008/11/010

Cited by 67 publications

(52 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…(11), (12), (18) and (19) one can get the following relation between the metric potentials ν and λ as…”

Section: The Field Equations and Their Solutions In F (R T ) Grmentioning

confidence: 99%

“…However, these works are mainly carried out by several authors in the framework of Einstein's general relativity [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. Though it is well known that Einstein's general relativity is a unique tool for uncovering many hidden mysteries of Nature, yet some observational evidences of the accelerating universe along with the existence of dark matter has imposed a theoretical challenge to this theory [20][21][22][23][24][25][26].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Gravastars in f(R,T) gravity

Das¹,

Ghosh²,

Guha³

et al. 2017

Phys. Rev. D

183

118

View full text Add to dashboard Cite

We propose a unique stellar model under the f (R, T ) gravity by using the conjecture of MazurMottola [P. Mazur and E. Mottola, Report number: LA-UR-01-5067., P. Mazur and E. Mottola, Proc. Natl. Acad. Sci. USA 101, 9545 (2004).] which is known as gravastar and a viable alternative to the black hole as available in literature. This gravastar is described by the three different regions, viz., (I) Interior core region, (II) Intermediate thin shell, and (III) Exterior spherical region. The pressure within the interior region is equal to the constant negative matter density which provides a repulsive force over the thin spherical shell. This thin shell is assumed to be formed by a fluid of ultrarelativistic plasma and the pressure, which is directly proportional to the matter-energy density according to Zel'dovich's conjecture of stiff fluid [Y.B. Zel'dovich, Mon. Not. R. Astron. Soc. 160, 1 (1972).], does counterbalance the repulsive force exerted by the interior core region. The exterior spherical region is completely vacuum and assumed to be de Sitter spacetime which can be described by the Schwarzschild solution. Under this specification we find out a set of exact and singularity-free solution of the gravastar which presents several other physically valid features within the framework of alternative gravity.

show abstract

“…(11), (12), (18) and (19) one can get the following relation between the metric potentials ν and λ as…”

Section: The Field Equations and Their Solutions In F (R T ) Grmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Gravastars in f(R,T) gravity

Das¹,

Ghosh²,

Guha³

et al. 2017

Phys. Rev. D

183

118

View full text Add to dashboard Cite

show abstract

“…Lately, we studied both types of gravastars [7][8][9][10][11], and found that, such configurations can indeed be constructed, although the region for the formation of them is very small in comparison to that of black holes.…”

Section: Introductionmentioning

confidence: 99%

Gravastars and black holes of anisotropic dark energy

2011

View full text Add to dashboard Cite

Dynamical models of prototype gravastars made of anisotropic dark energy are constructed, in which an infinitely thin spherical shell of a perfect fluid with the equation of state p = (1 − γ )σ divides the whole spacetime into two regions, the internal region filled with a dark energy fluid, and the external Schwarzschild region. The models represent "bounded excursion" stable gravastars, where the thin shell is oscillating between two finite radii, while in other cases they collapse until the formation of black holes. Here we show, for the first time in the literature, a model of gravastar and formation of black hole with both interior and thin shell constituted exclusively of dark energy. Besides, the sign of the parameter of anisotropy ( p t − p r ) seems to be relevant to the gravastar formation. The formation is favored when the tangential pressure is greater than the radial pressure, at least in the neighborhood of the isotropic case (ω = −1).

show abstract

“…Based on the discussions about the gravastar picture some authors have proposed alternative models [59][60][61][62][63]. Among them, we can find a Chaplygin dark star [64], a gravastar supported by non-linear electrodynamics [65], a gravastar with continuous anisotropic pressure [66].…”

mentioning

confidence: 99%

Star models with dark energy

2009

View full text Add to dashboard Cite

We have constructed star models consisting of four parts: (i) a homogeneous inner core with anisotropic pressure (ii) an infinitesimal thin shell separating the core and the envelope; (iii) an envelope of inhomogeneous density and isotropic pressure; (iv) an infinitesimal thin shell matching the envelope boundary and the exterior Schwarzschild spacetime. We have analyzed all the energy conditions for the core, envelope and the two thin shells. We have found that, in order to have static solutions, at least one of the regions must be constituted by dark energy. The results show that there is no physical reason to have a superior limit for the mass of these objects but for the ratio of mass and radius.

show abstract

Stable and ‘bounded excursion’ gravastars, and black holes in Einstein’s theory of gravity

Cited by 67 publications

References 20 publications

Gravastars in f(R,T) gravity

Gravastars in f(R,T) gravity

Gravastars and black holes of anisotropic dark energy

Star models with dark energy

Contact Info

Product

Resources

About