Nonsingular cosmological models: the massive scalar field case

Sathyaprakash, B. S. ; Sinha, K. P. (1988) Nonsingular cosmological models: the massive scalar field case Pramana - Journal of Physics, 30 (1). pp. 15-27. ISSN 0304-4289


Official URL:

Related URL:


The nonminimal coupling of a massive self-interacting scalar field with a gravitational field is studied. Spontaneous symmetry breaking occurs in the open universe even when the sign on the mass term is positive. In contrast to grand unified theories, symmetry breakdown is more important for the early universe and it is restored only in the limit of an infinite expansion. Symmetry breakdown is shown to occur in flat and closed universes when the mass term carries a wrong sign. The model has a naturally defined effective gravitational coupling coefficient which is rendered time-dependent due to the novel symmetry breakdown. It changes sign below a critical value of the cosmic scale factor indicating the onset of a repulsive field. The presence of the mass term severely alters the behaviour of ordinary matter and radiation in the early universe. The total energy density becomes negative in a certain domain. These features make possible a nonsingular cosmological model for an open universe. The model is also free from the horizon and the flatness problems.

Item Type:Article
Source:Copyright of this article belongs to Indian Academy of Sciences.
Keywords:Symmetry Breaking; Cosmology; Nonsingular Cosmological Models
ID Code:48113
Deposited On:14 Jul 2011 10:24
Last Modified:18 May 2016 03:27

Repository Staff Only: item control page