The Boulware vacuum RVP and RSET for spherical thin shells are computed analytically near the surface and center, and numerically throughout, showing finite interior effects and rapid exterior convergence to Schwarzschild values in the black-hole limit.
Gravastars must have anisotropic pressures
4 Pith papers cite this work. Polarity classification is still indexing.
4
Pith papers citing it
abstract
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 -- anisotropic pressures in the "crust" of a gravastar-like object are unavoidable. The anisotropic TOV equation can then be used to bound the pressure anisotropy. The transverse stresses that support a gravastar permit a higher compactness than is given by the Buchdahl--Bondi bound for perfect fluid stars. Finally we comment on the qualitative features of the equation of state that gravastar material must have if it is to do the desired job of preventing horizon formation.
citation-role summary
background 2
citation-polarity summary
fields
gr-qc 4roles
background 2polarities
background 2representative citing papers
A constructive algorithm yields NEC-obeying static spherical metrics with g_tt g_rr = -1, including a log-corrected Schwarzschild geometry that can mimic black holes.
Re-derivation of the constant-density star in isotropic coordinates produces a transparent metric and highlights under-appreciated special cases including pressure gravitating alone and naked singularities.
Current and future observations can test whether dark compact objects are Kerr black holes or exotic alternatives, with null results strengthening the black hole paradigm.
citing papers explorer
-
Vacuum polarization and renormalized stress-energy tensor of spherical thin shells
The Boulware vacuum RVP and RSET for spherical thin shells are computed analytically near the surface and center, and numerically throughout, showing finite interior effects and rapid exterior convergence to Schwarzschild values in the black-hole limit.
-
Energy conditions in static, spherically symmetric spacetimes and effective geometries
A constructive algorithm yields NEC-obeying static spherical metrics with g_tt g_rr = -1, including a log-corrected Schwarzschild geometry that can mimic black holes.
-
Revisiting Schwarzschild's constant density star in isotropic coordinates
Re-derivation of the constant-density star in isotropic coordinates produces a transparent metric and highlights under-appreciated special cases including pressure gravitating alone and naked singularities.
-
Testing the nature of dark compact objects: a status report
Current and future observations can test whether dark compact objects are Kerr black holes or exotic alternatives, with null results strengthening the black hole paradigm.