Armenian Journal of Physics

THE COSMOLOGICAL REPULSION IN PRESENCE OF SCALARS FIELDS

Chubaryan, E. and Avagyan, R. and Harutyunyan, G. (2013) THE COSMOLOGICAL REPULSION IN PRESENCE OF SCALARS FIELDS. Armenian Journal of Physics, 6 (1). pp. 7-34. ISSN 1829-1171

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Abstract

The recently discovered accelerated expansion of the Universe is of great interest in theoretical research on the evolution of the Universe. The cause of this expansion presumably is the presence of dark energy, which has been estimated to form up to 74% of the Universe and generates a “repulsive force”. In this paper a cosmological model is constructed which takes the dark energy into account in a Jordan–Brans–Dicke tensor-scalar theory with a non-minimally coupled scalar field in the presence of a cosmological scalar. We consider 4 classes of cosmological models. The first class is the models of solutions in the proper frame of JBD theory with non-minimally coupled scalar field dominations, in the presence of cosmological scalar, which is becoming to the conventional cosmological constant  in Einstein frame under a conformal transformation. These models accept the possibility of uniform expansion and then of the accelerated expansion appear in cosmological times. The second class considers cosmological models in the framework of the Jordan–Brans–Dicke (JBD) theory in the Einstein frame. The cases of scalar field and the presence of cosmological constant with the matter being described by barometric equation of state is pressure, is energy density) are discussed separately. The analysis of obtained result is carried out in the light of modern observational data. It is shown that the contribution of the scalar field and  in the case of is “decelerating” parameter) compensate each other, thus leading to Einstein’s theory. In the third class the problem is solved for the radiation dominated epoch. Numerical calculations are done for models with different values of the dimensionless coupling constant In the last section a conformal coupled scalar field is considered.

Item Type:Article
Subjects:Physics > 03.Quantum mechanics, field theories, and special relativity
ID Code:576
Deposited By:Prof. Vladimir Aroutiounian
Deposited On:28 Mar 2013 12:41
Last Modified:28 Mar 2013 13:06

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