Cosmological models with constant deceleration parameter in BransDicke theory
Abstract
A detailed study of cosmological models with constant deceleration parameterq is undertaken in the framework of BransDicke theory. These models are divided into two categories: (i) singular models with expansion driven by bigbang impulse, (ii) nonsinglar models with expansion driven by creation of matter particles. Prigogine's hypothesis of creation of matter out of gravitational energy is analysed and extended to BD cosmology. To accommodate the creation of new particles, the universe is regarded as an open thermodynamical system and the energy conservation equation is modified with the incorporation of a creation pressure termp _{ c } in the energymomentum tensortilde T_{ab} . The exact solutions of the field equations of BD theory withtilde T_{ab} are obtained using the power law relationΦ=KR ^{α}, which leads to models with constantq. The behaviour of the solutions is investigated for different range of values ofa. The role played by the BD scalar fieldΦ and creation of matter particles in the expansion of the universe is investigated. It is found that one particular model with constantq has exponential expansion.
 Publication:

General Relativity and Gravitation
 Pub Date:
 December 1994
 DOI:
 10.1007/BF02106714
 Bibcode:
 1994GReGr..26.1217J