Uniform anisotropic cosmological model with string source

Axially Symmetric Cosmic Strings in a Scalar-Tensor Theory

“…Also, the physical quantities like energy density and tension density of the string diverge in this theory while they do not in Brans-Dicke theory. However, the string models in general relativity obtained by Bhattacharya and Karade (1993), Chakraborty and Chakraborty (1992) and models presented by Reddy and Rao (2006) in Lyra manifold are quite similar to the string models discussed here.…”

“…Recently, Reddy (2003a,b) has obtained string cosmological models in Brans-Dicke (1961) and Saez-Ballester (1985) scalar-tensor theories of gravitation with equation of state for string density,…”

“…Brans and Dicke (1961) introduced a scalar-tensor theory of gravitation involving a scalar function in addition to the familiar general relativistic metric tensor. In this theory the scalar field has the dimension of inverse of the gravitational constant and its role is confined to its effects on gravitational field equations.…”

A Xially Symmetric Cosmic Strings and Domain Walls in Lyra Geometry

“…Relativistic string models in the context of Bianchi space times have been obtained by Krori et al (1990), Banerjee et al (1990) and Tikekar and Patel (1990) while Tikekar et al (1994) have presented a class of cylindrically symmetric string models. Bhattacharjee and Baruah (2001) studied the problem of cosmic strings in Bianchi type cosmologies D.R.K. Reddy ( ) · M.V.…”

On axially symmetric space–times admitting homothetic vector fields in Lyra’s geometry

“…holds where ψ is a constant (the homothetic constant) on M , £ denotes a Lie derivative and ∇ is the covariant derivative, such that Consider the axially symmetric metric in the form [42] 5) with the convention x 0 = t, x 1 = χ, x 2 = φ, x 3 = z and A and B are functions of t only while f is a function of the coordinate χ only.…”