Gravastar Shadows

@inproceedings{Sakai2014GravastarS,
  title={Gravastar Shadows},
  author={Nobuyuki Sakai and Hiromi Saida and Takashi Tamaki},
  year={2014}
}
Direct observation of black holes is one of the grand challenges in astronomy. If there are supercompact objects which possess unstable circular orbits of photons, however, it may be difficult to distinguish them from black holes by observing photons. As a model of super-compact objects, we consider a gravastar (gravitational-vacuum-star) which was originally proposed by Mazur and Mottola. For definiteness, we adopt a spherical thin-shell model of a gravastar developed by Visser and Wiltshire… 
Observational signatures of strongly naked singularities: image of the thin accretion disk
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The data from the event horizon telescope have provided a novel view of the vicinity of the horizon of a black hole (BH), by imaging the region around the light-ring. They have also raised hopes for
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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
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One crucial problem in relativistic astrophysics is that of the nature of black hole candidates. It is usually assumed that astrophysical black holes are described by the Schwarzschild or Kerr
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Testing general relativity with the Event Horizon Telescope
  • D. Psaltis
  • Physics
    General Relativity and Gravitation
  • 2019
The Event Horizon Telescope is a millimeter VLBI array that aims to take the first pictures of the black holes in the center of the Milky Way and of the M87 galaxy, with horizon scale resolution.
Spherical polytropic balls cannot mimic black holes
The so-called black hole shadow is a dark region which is expected to appear in a fine image of optical observation of black holes. It is essentially an absorption cross section of black hole, and
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