# Stable gravastars of anisotropic dark energy

## Abstract

Dynamical models of prototype gravastars made of anisotropic dark energy fluid are constructed, 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, the internal region is filled with an anisotropic dark energy fluid, and the external region is the Schwarzschild. It is found that in some cases the models represent the ''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 or normal stars. In the phase space, the region for the ''bounded excursion'' gravastars is very small in comparison to that of black holes, but not empty, as found in our previous papers. Therefore, although the existence of gravastars can not be completely excluded from current analysis, the opposite is not possible either, that is, even if gravastars exist, they do not exclude the existence of black holes.

- Authors:

- Coordenacao de Astronomia e Astrofisica, Observatorio Nacional, Rua General Jose Cristino 77, Sao Cristovao 20921-400, Rio de Janeiro, RJ (Brazil)
- 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)
- GCAP-CASPER, Department of Physics, Baylor University, Waco, TX 76798 (United States)

- Publication Date:

- OSTI Identifier:
- 22156931

- Resource Type:
- Journal Article

- Journal Name:
- Journal of Cosmology and Astroparticle Physics

- Additional Journal Information:
- Journal Volume: 2009; Journal Issue: 03; 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; ANISOTROPY; BLACK HOLES; EQUATIONS OF STATE; IDEAL FLOW; NONLUMINOUS MATTER; PHASE SPACE; SPACE-TIME; SPHERICAL CONFIGURATION; STARS

### Citation Formats

```
Chan, R., Silva, M.F.A. da, Rocha, P., and Wang, Anzhong, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: pedrosennarocha@gmail.com, E-mail: anzhong_wang@baylor.edu.
```*Stable gravastars of anisotropic dark energy*. United States: N. p., 2009.
Web. doi:10.1088/1475-7516/2009/03/010.

```
Chan, R., Silva, M.F.A. da, Rocha, P., & Wang, Anzhong, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: pedrosennarocha@gmail.com, E-mail: anzhong_wang@baylor.edu.
```*Stable gravastars of anisotropic dark energy*. United States. doi:10.1088/1475-7516/2009/03/010.

```
Chan, R., Silva, M.F.A. da, Rocha, P., and Wang, Anzhong, E-mail: chan@on.br, E-mail: mfasnic@gmail.com, E-mail: pedrosennarocha@gmail.com, E-mail: anzhong_wang@baylor.edu. Sun .
"Stable gravastars of anisotropic dark energy". United States. doi:10.1088/1475-7516/2009/03/010.
```

```
@article{osti_22156931,
```

title = {Stable gravastars of anisotropic dark energy},

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

abstractNote = {Dynamical models of prototype gravastars made of anisotropic dark energy fluid are constructed, 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, the internal region is filled with an anisotropic dark energy fluid, and the external region is the Schwarzschild. It is found that in some cases the models represent the ''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 or normal stars. In the phase space, the region for the ''bounded excursion'' gravastars is very small in comparison to that of black holes, but not empty, as found in our previous papers. Therefore, although the existence of gravastars can not be completely excluded from current analysis, the opposite is not possible either, that is, even if gravastars exist, they do not exclude the existence of black holes.},

doi = {10.1088/1475-7516/2009/03/010},

journal = {Journal of Cosmology and Astroparticle Physics},

issn = {1475-7516},

number = 03,

volume = 2009,

place = {United States},

year = {2009},

month = {3}

}