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Exact Solution and Exotic Fluid in Cosmology
Department of Physics and Institute of Basic Science, Sungkyunkwan University, Suwon 440-746, Korea
Center for Quantum Space-time, Sogang University, Seoul 121-742, Korea
* Author to whom correspondence should be addressed.
Received: 21 August 2012; in revised form: 13 September 2012 / Accepted: 17 September 2012 / Published: 20 September 2012
Abstract: We investigate cosmological consequences of nonlinear sigma model coupled with a cosmological fluid which satisfies the continuity equation. The target space action is of the de Sitter type and is composed of four scalar fields. The potential which is a function of only one of the scalar fields is also introduced. We perform a general analysis of the ensuing cosmological equations and give various critical points and their properties. Then, we show that the model exhibits an exact cosmological solution which yields a transition from matter domination into dark energy epoch and compare it with the Λ-CDM behavior. Especially, we calculate the age of the Universe and show that it is consistent with the observational value if the equation of the state ωf of the cosmological fluid is within the range of 0.13 < ωf < 0.22. Some implication of this result is also discussed.
Keywords: dark energy; nonlinear sigma model; de Sitter
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Kouwn, S.; Moon, T.; Oh, P. Exact Solution and Exotic Fluid in Cosmology. Entropy 2012, 14, 1771-1783.
Kouwn S, Moon T, Oh P. Exact Solution and Exotic Fluid in Cosmology. Entropy. 2012; 14(9):1771-1783.
Kouwn, Seyen; Moon, Taeyoon; Oh, Phillial. 2012. "Exact Solution and Exotic Fluid in Cosmology." Entropy 14, no. 9: 1771-1783.