# Stable and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity

## Abstract

Dynamical models of prototype gravastars are constructed and studied. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of a perfect fluid with the equation of state p = (1-{gamma}){sigma} divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. When {gamma}<1 and {Lambda}{ne}0, it is found that in some cases the models represent stable gravastars, and in some cases they represent 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in some other cases they collapse until the formation of black holes occurs. However, when {gamma}{>=}1, even with {Lambda}{ne}0, only black holes are found. In the phase space, the region for both stable gravastars and 'bounded excursion' gravastars is very small in comparison to that for black holes, although it is not completely empty.

- Authors:

- Departamento de Fisica Teorica, Instituto de Fisica, Universidade do Estado do Rio de Janeiro, Rua Sao Francisco Xavier 524, Maracana 20550-900, Rio de Janeiro, RJ (Brazil)
- Coordenacao de Astronomia e Astrofisica, Observatorio Nacional, Rua General Jose Cristino, 77, Sao Cristovao 20921-400, Rio de Janeiro, RJ (Brazil)

- Publication Date:

- OSTI Identifier:
- 22156816

- Resource Type:
- Journal Article

- Journal Name:
- Journal of Cosmology and Astroparticle Physics

- Additional Journal Information:
- Journal Volume: 2008; Journal Issue: 11; Other Information: Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 1475-7516

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; BLACK HOLES; DE SITTER SPACE; EQUATIONS OF STATE; GENERAL RELATIVITY THEORY; IDEAL FLOW; PHASE SPACE; SCHWARZSCHILD METRIC; SPACE-TIME; SPHERICAL CONFIGURATION

### Citation Formats

```
Rocha, P, Da Silva, M F A, Wang, Anzhong, and Chan, R, E-mail: pedrosennarocha@gmail.com, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: anzhong_wang@baylor.edu.
```*Stable and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity*. United States: N. p., 2008.
Web. doi:10.1088/1475-7516/2008/11/010.

```
Rocha, P, Da Silva, M F A, Wang, Anzhong, & Chan, R, E-mail: pedrosennarocha@gmail.com, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: anzhong_wang@baylor.edu.
```*Stable and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity*. United States. doi:10.1088/1475-7516/2008/11/010.

```
Rocha, P, Da Silva, M F A, Wang, Anzhong, and Chan, R, E-mail: pedrosennarocha@gmail.com, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: anzhong_wang@baylor.edu. Sat .
"Stable and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity". United States. doi:10.1088/1475-7516/2008/11/010.
```

```
@article{osti_22156816,
```

title = {Stable and 'bounded excursion' gravastars, and black holes in Einstein's theory of gravity},

author = {Rocha, P and Da Silva, M F A and Wang, Anzhong and Chan, R, E-mail: pedrosennarocha@gmail.com, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: anzhong_wang@baylor.edu},

abstractNote = {Dynamical models of prototype gravastars are constructed and studied. The models are the Visser-Wiltshire three-layer gravastars, in which an infinitely thin spherical shell of a perfect fluid with the equation of state p = (1-{gamma}){sigma} divides the whole spacetime into two regions, where the internal region is de Sitter, and the external one is Schwarzschild. When {gamma}<1 and {Lambda}{ne}0, it is found that in some cases the models represent stable gravastars, and in some cases they represent 'bounded excursion' stable gravastars, where the thin shell is oscillating between two finite radii, while in some other cases they collapse until the formation of black holes occurs. However, when {gamma}{>=}1, even with {Lambda}{ne}0, only black holes are found. In the phase space, the region for both stable gravastars and 'bounded excursion' gravastars is very small in comparison to that for black holes, although it is not completely empty.},

doi = {10.1088/1475-7516/2008/11/010},

journal = {Journal of Cosmology and Astroparticle Physics},

issn = {1475-7516},

number = 11,

volume = 2008,

place = {United States},

year = {2008},

month = {11}

}