Carvalho FC, Alcaniz JS, Lima JAS, Silva R. Scalar-field-dominated cosmology with a transient acceleration phase.
PHYSICAL REVIEW LETTERS 2006;
97:081301. [PMID:
17026287 DOI:
10.1103/physrevlett.97.081301]
[Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2006] [Indexed: 05/12/2023]
Abstract
A new cosmological scenario driven by a slow rolling homogeneous scalar field whose exponential potential V(Phi) has a quadratic dependence on the field Phi in addition to the standard linear term is discussed. The derived equation of state for the field predicts a transient accelerating phase, in which the Universe was decelerated in the past, began to accelerate at redshift z approximately 1, is currently accelerated, but, finally, will return to a decelerating phase in the future. This overall dynamic behavior is profoundly different from the standard evolution of the cold dark matter model with a cosmological constant, and may alleviate some conflicts in reconciling the idea of a dark-energy-dominated universe with observables in String or M theory. Some theoretical predictions for the present scalar field plus dark matter dominated stage are confronted with cosmological observations in order to test the viability of the scenario.
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