Anisotropic Bianchi Type-II Cosmological Models in Self-Creation Cosmology

Totally anisotropic Bianchi type-II cosmological solutions are presented in Barber's second self-creation theory of gravitation both in vacuum and in the presence of stiff-matter. The corresponding cosmological models have no finite singularity. The stiff-matter model gives essentially an empty universe for large time. Some physical and kinematical properties of the models are discussed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Propagation of magnetogasdynamic spherical shock waves in an exponential decreasing medium

By use of the approximate method of Whitham (1958) the effect of magnetic field is investigated on a point explosion in a medium exihibiting exponential decrease of density and temperature. It has been found that the shock velocity and shock Mach number first decrease, but after a certain distance they start increasing.     

Effect of oblateness on triangular solutions at critical mass

At critical mass the triangular equilibria in the planar restricted three-body problem, when the more massive primary is an oblate spheroid with its equatorial plane coincident with the plane of motion, are in general unstable due to the presence of secular terms in the solutions of linearized equations of motion in the vicinity of these points. Existence of retrograde elliptic periodic orbits is established through suitable velocity components. The eccentricity of these orbits increases with the oblateness.     

The LRS Bianchi type-I perfect fluids space-times

An algorithm is derived for constructing spatially-homogeneous perfect fluid solutions of Einstein's field equations which are of Bianchi type-I and are locally rotationally-symmetric. Starting from Bayin and Krisch solution a new exact solution is obtained. Some physical and kinematic properties of the cosmological model are discussed.     

Non-uniform propagation of weak waves through thermally-conducting and dissociating gases

Non-uniform propagation of weak discontinuities headed by wavefronts of arbitrary shape along bi-characteristics of a hyperbolic system through thermally-conducting and dissociating gases are studied. An explicit criterion for the growth and decay of weak waves along bi-characteristic curves in the characteristic manifold of the governing differential equations is given. The two fundamental theorems on the global behaviour of the time-dependent wave amplitude of a weak wave has been concluded.     

A class of new Bianchi I perfect fluid space-times

A procedure to generate new exact solutions to Einstein equations for perfect fluids is applied to LRS Bianchi type I line-element. Starting from some known solutions a class of new perfect fluid solutions of Bianchi type I are presented. The physical and kinematical properties of spatially homogeneous and anisotropic cosmological models are studied.     

Hall effects on heat and mass transfer flow through porous medium

Effects of Hall current on free convection and mass transfer flow through a porous medium bounded by a vertical surface has been analysed. The problem is solved analytically. The velocity profiles are shown on graphs. Effects ofm (Hall parameter).K ^* (permeability parameter), and Sc (Schmidt number) on velocity are discussed.     

Heat and mass transfer in convective flow of an incompressible rarefied visco-elastic fluid in presence of transverse magnetic field

Analytical study is performed to examine heat and mass transfer characteristics of natural convection flow of an incompressible, rarefied visco-elastic fluid past an infinite vertical porous plate with constant suction in the presence of transverse magnetic field under combined buoyancy force effects of thermal and mass diffusion. The effects of various parameters on mean velocity and mean skin-friction are shown graphically followed by a comparative study of Newtonian and non-Newtonian (visco-elastic). rarefied states.