English

Gravitational-thermodynamic instabilities of isothermal spheres in dS and AdS

General Relativity and Quantum Cosmology 2013-05-22 v1 Cosmology and Nongalactic Astrophysics

Abstract

Thermodynamical stability of fluid spheres is studied in the presence of a cosmological constant, both in the Newtonian limit, as well as in General Relativity. In all cases, an increase of the cosmological constant tends to stabilize the system, making asymptotically de Sitter space more thermodynamically stable than anti-de Sitter at the purely classical level. In addition, in the Newtonian case reentrant phase transitions are observed for a positive cosmological constant, due to its repelling property in this case. In General Relativity is studied the case of radiation, for which is found that the critical radius, at which an instability sets in, is always bigger than the black hole radius of the system and furthermore, at some value of the cosmological constant this critical radius hits at the cosmological horizon.

Keywords

Cite

@article{arxiv.1305.4851,
  title  = {Gravitational-thermodynamic instabilities of isothermal spheres in dS and AdS},
  author = {Zacharias Roupas},
  journal= {arXiv preprint arXiv:1305.4851},
  year   = {2013}
}

Comments

Proceedings contribution; much of the work presented in this talk was elaborated jointly with Minos Axenides and George Georgiou, and appears analytically elsewhere