Phantom dark energy models with a nearly flat potential
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)
We examine phantom dark energy models produced by a field with a negative kinetic term and a potential that satisfies the slow-roll conditions: [(1/V)(dV/d{phi})]{sup 2}<<1 and (1/V)(d{sup 2}V/d{phi}{sup 2})<<1. Such models provide a natural mechanism to produce an equation of state parameter, w, slightly less than -1 at present. Using techniques previously applied to quintessence, we show that in this limit, all such phantom models converge to a single expression for w(a), which is a function only of the present-day values of {omega}{sub {phi}} and w. This expression is identical to the corresponding behavior of w(a) for quintessence models in the same limit. At redshifts z < or approx. 1, this limiting behavior is well fit by the linear parametrization, w=w{sub 0}+w{sub a}(1-a), with w{sub a}{approx_equal}-1.5(1+w{sub 0})
- OSTI ID:
- 21254226
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 78, Issue 6; Other Information: DOI: 10.1103/PhysRevD.78.067303; (c) 2008 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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