Lyra's Cosmology of Massive String in Anisotropic Bianchi-II Space-time

TL;DR

This paper explores anisotropic Bianchi II cosmological models with massive strings in Lyra's geometry, solving modified Einstein equations to understand universe evolution from big bang to future, aligning with observations.

Contribution

It introduces solutions for Bianchi II models with massive strings in Lyra's manifold, analyzing their implications for universe dynamics and string disappearance over time.

Findings

Displacement field decreases over time, approaching a small positive value.

Massive strings dominate early universe and vanish at large times.

Solutions include power law for past evolution and exponential law for future projection.

Abstract

The paper deals with a spatially homogeneous and totally anisotropic Bianchi II cosmological models representing massive strings in normal gauge for Lyra's manifold. The modified Einstein's field equations have been solved by applying variation law for Hubble's parameter. This law generates two type of solutions for average scale factor, one is of power law type and other is of exponential law type. The power law describes the dynamics of Universe from big bang to present epoch while exponential law seems reasonable to project dynamics of future Universe. It has been found that the displacement actor $(\beta)$ is a decreasing function of time and it approaches to small positive value at late time, which is collaborated with Halford (1970) as well as recent observations of SN Ia. The study reveals that massive strings dominate in early Universe and eventually disappear from Universe for sufficiently large time, which is in agreement with the current astronomical observations.