Phantom dark energy, cosmic doomsday, and the coincidence problem
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)
Phantom dark-energy models, with w<-1, are characterized by a future singularity and therefore a finite lifetime for the universe. Because the future singularity is triggered by the onset of dark-energy domination, the universe spends a significant fraction of its total lifetime in a state for which the dark-energy and matter densities are roughly comparable. We calculate, as a function of w, the fraction of the total lifetime of the universe for which the dark-energy and matter densities differ by less than the ratio r{sub 0} in either direction. For r{sub 0}=10, this fraction varies from 1/3 to 1/8 as w varies from -1.5 to -1.1; the fraction is smaller for smaller values of r{sub 0}. This result indicates that the coincidence problem is significantly ameliorated in phantom-dominated cosmologies with a future singularity.
- OSTI ID:
- 20706186
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 71, Issue 6; Other Information: DOI: 10.1103/PhysRevD.71.063519; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA); ISSN 0556-2821
- Country of Publication:
- United States
- Language:
- English
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