String cosmological models with bulk viscosity in Nordtvedt’s general scalar-tensor theory of gravitation

Authors

• Uma Maheswara Rao Velagapudi ¹
• Neelima Davuluri ¹

• Department of Applied Mathematics, Andhra University

Abstract

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.

Keywords

• Bulk viscosity
• And IX metrics
• Bianchi type II
• Cosmic strings
• Nordtvedt' s general scalar
• Tensor theory
• VIII