# Gravastars must have anisotropic pressures

@article{Cattoen2005GravastarsMH, title={Gravastars must have anisotropic pressures}, author={C'eline Cattoen and Tristan Faber and Matt Visser}, journal={Classical and Quantum Gravity}, year={2005}, volume={22}, pages={4189 - 4202} }

One of the very small number of serious alternatives to the usual concept of an astrophysical black hole is the ‘gravastar’ model developed by Mazur and Mottola, and a related phase-transition model due to Laughlin et al. We consider a generalized class of similar models that exhibit continuous pressure—without the presence of infinitesimally thin shells. By considering the usual TOV equation for static solutions with negative central pressure, we find that gravastars cannot be perfect fluids…

## 209 Citations

Probing the stability of gravastars by dropping dust shells onto them

- Physics
- 2010

As a preparation for the dynamical investigations, this paper begins with a short review of the three-layer gravastar model with distinguished attention to the structure of the pertinent parameter…

Gravastars in f(𝕋,𝒯) gravity

- Physics
- 2020

We propose a stellar model under the [Formula: see text] gravity following Mazur–Mottola’s conjecture[Formula: see text] known as gravastar which is generally believed as a viable alternative to…

Study of gravastars in Rastall gravity

- PhysicsJournal of Cosmology and Astroparticle Physics
- 2021

Gravastars have been considered as a feasible alternative to black holes in the past couple of decades. Stable models of gravastar have been studied in many of the alternative gravity theories…

Gravastar solutions with continuous pressures and equation of state

- Physics
- 2005

We study the gravitational vacuum star (gravastar) configuration as proposed by Cattoen et al (2005 Class. Quantum Grav. 22 4189) in a model where the interior de Sitter spacetime segment is…

Gravastar: An alternative to black hole

- Physics, Geology
- 2020

In this work, we review thoroughly the origin, development and present status of gravastar which has been thought to be an alternative to black hole along with its future feasibility in the sense of…

Black holes as frozen stars

- PhysicsPhysical Review D
- 2022

We have recently proposed a model for a regular black hole, or an ultra-compact object, that is premised on having maximally negative radial pressure throughout the entirety of the object’s interior.…

Gravastars and black holes of anisotropic dark energy

- Physics
- 2011

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…

## References

SHOWING 1-10 OF 61 REFERENCES

Stable gravastars—an alternative to black holes?

- Physics
- 2004

The 'gravastar' picture developed by Mazur and Mottola is one of a very small number of serious challenges to our usual conception of a 'black hole'. In the gravastar picture there is effectively a…

Some conditions for existence of tension stars

- Physics
- 1994

We re-examine the exact solution of the Einstein perfect-fluid field equations with constant-density equation of state to study the conditions under which negative pressures, or tensions (generated,…

ANISTROPIC STARS: EXACT SOLUTIONS AND STABILITY

- Physics
- 2004

I report on recent work concerning the existence and stability of self-gravitating spheres with anisotropic pressure. After presenting new exact solutions, Chandrasekhar's variational formalism for…

Scalar Black Holes

- Physics
- 1998

A class of exact regular spherically symmetric solutions to the Einstein equation obeying Dymnikova's definition of the vacuumlike state is considered. These solutions, which may be interpreted as…

Gravitational condensate stars: An alternative to black holes

- Physics
- 2001

A new solution for the endpoint of gravitational collapse is proposed. By extending the concept of Bose-Einstein condensation to gravitational systems, a cold, compact object with an interior de…

Bounds on the interior geometry and pressure profile of static fluid spheres

- Physics
- 2003

It is a famous result of relativistic stellar structure that (under mild technical conditions) a static fluid sphere satisfies the Buchdahl–Bondi bound 2M/R < 8/9; the surprise here being that the…

Bounds on 2m/R for static spherical objects

- Mathematics
- 1999

It is well known that a spherically symmetric constant density static star, modeled as a perfect fluid, possesses a bound on its mass m by its radial size R given by 2m/R \le 8/9 and that this bound…

Emergent Relativity

- Physics
- 2003

A possible resolution of the incompatibility of quantum mechanics and general relativity is that the relativity principle is emergent. I show that the central paradox of black holes also occurs at a…

Thin shells in general relativity and cosmology: The lightlike limit.

- PhysicsPhysical review. D, Particles and fields
- 1991

This paper shows how the structure and dynamics of a thin shell traveling at the speed of light can be obtained from a simple and convenient prescription that is a straightforward extension and…