Bianchi type-I universe in the presence of zero-mass scalar fields

An exact Bianchi type-I cosmological model in the presence of zero-mass scalar fields is obtained when the source of the gravitational field is a perfect fluid with pressure equal to energy density. Some properties of the model are discussed.     

Magnetic expression of some major lineaments and Cretaceous quiet zone in the Bay of Bengal

 Magnetic data over the eastern continental margin of India and adjacent Bengal fan demarcate two major lineaments. A high amplitude N–S-trending lineation of the Cauvery offshore Basin corresponds to the offshore fragment of the 80°E lineament recorded onland. A N–S lineation of very high amplitude anomaly off Chilka lake considered as the possible northward extension of the 85°E ridge delineated, hitherto in Bengal Fan. A subdued magnetic anomaly zone is demarcated seaward of the continent–ocean boundary (COB) in the Bengal Fan. Over the northern Bengal Fan this zone is delineated east of 85°E lineation. This quiet zone might have evolved during the Early Cretaceous period of normal magnetic polarity between M0 and 34 (120–84 Ma) anomalies. Received: 6 April 1995 / Revision received: 3 September 1996     

Exact Bianchi type-II Lyttleton-Bondi universe

The exterior field of the Bianchi type-II metric in the Lyttleton-Bondi universe is considered and an exact cosmological model is presented. The behaviour of the model is also discussed.     

Vacuum bianchi type V and VI0 cosmological models in a new scalar-tensor theory of gravitation

Vacuum Bianchi type V and VI₀ cosmological models obtained in a new scalar-tensor theory of gravitation proposed by Schmidtet al. Some physical properties of these models are also discussed.     

Bianchi type-VI0 models in self-creation cosmology

Spatially-homogenous and anisotropic Bianchi type-VI₀ cosmological models are obtained, in Barber's second self-creation theory of gravitation, both in vacuum and in the presence of perfect fluid with pressure equal to energy density. Some properties of the model are discussed.     

Birkhoff-type theorem for electromagnetic fields in self-creation cosmology

A result having formal similarity to Birkhoff's theorem in general relativity has been proved in the presence of electromagnetic fields in a self-creation theory of gravitation proposed by Barber, when the scalar field is independent of time.