Future island universes in a background universe accelerated by a cosmological constant and by quintessence

Jul, 2001
13 pages
Published in:
  • Phys.Rev.D 65 (2002) 123518
e-Print:

Citations per year

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Abstract: (arXiv)
We study bound object formation in a background universe accelerated by cosmological constant and by quintessence. If the acceleration lasts forever, due to the existence of event horizon, one would have naively expected the universe to approach a state of cold death. However, we find that many local regions in the universe can in fact be protected by their own gravity to form mini-universes, provided that their present matter densities exceed some critical value. In the case with cosmological constant (Λ\LambdaCDM cosmology) the condition of forming mini-universe is that the ratio of present density parameters Ωi0/ΩΛ\Omega_{i}^0/\Omega_\Lambda ought to be larger than a critical value 3.63. Such mini-universes typically weigh less than 2×10142\times 10^{14} solar masses, with the lighter ones having tight and compact configurations. In the case with quintessence, the final ratio Ωi/Ωq\Omega_i/\Omega_q of a mini-universe is found to be always larger than wq2wqw_q^2-w_q, where wqw_q is the equation of state parameter.
  • 98.80.Es
  • cosmological constant
  • quintessence
  • cosmological model
  • bound state
  • background: expansion
  • numerical calculations