String cosmological models with bulk viscosity in Nordtvedt's general scalar-tensor theory of gravitation
محورهای موضوعی : Journal of Theoretical and Applied PhysicsUma Maheswara Rao Velagapudi 1 , Neelima Davuluri 2
1 - Department of Applied Mathematics, Andhra University
2 - Department of Applied Mathematics, Andhra University
کلید واژه: Bulk viscosity, Cosmic strings, Bianchi type II, VIII, and IX metrics, Nordtvedt' s general scalar, tensor theory,
چکیده مقاله :
AbstractWe have obtained and presented spatially homogeneous Bianchi types II, VIII, and IX string cosmological models with bulk viscosity in Nordtvedt's (Astrophys. J. 161:1059, 1970) general scalar-tensor theory of gravitation with the help of a special case proposed by Schwinger. It is observed that only the bulk viscous cosmological model exists in the case of Bianchi type IX universe. Some important features of the models, thus obtained, have been discussed.