Hilltop quintessence
- Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States)
We examine hilltop quintessence models, in which the scalar field is rolling near a local maximum in the potential, and w{approx_equal}-1. We first derive a general equation for the evolution of {phi} in the limit where w{approx_equal}-1. We solve this equation for the case of hilltop quintessence to derive w as a function of the scale factor; these solutions depend on the curvature of the potential near its maximum. Our general result is in excellent agreement ({delta} < or approx. 0.5%) with all of the particular cases examined. It works particularly well ({delta}w < or approx. 0.1%) for the pseudo-Nambu-Goldstone boson potential. Our expression for w(a) reduces to the previously-derived slow-roll result of Sen and Scherrer in the limit where the curvature goes to zero. Except for this limiting case, w(a) is poorly fit by linear evolution in a.
- OSTI ID:
- 21251114
- Journal Information:
- Physical Review. D, Particles Fields, Vol. 78, Issue 12; Other Information: DOI: 10.1103/PhysRevD.78.123525; (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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