Some LRS Bianchi-I String Cosmological Models with Variable Deceleration Parameter

TL;DR

This paper develops LRS Bianchi-I cosmological models with massive strings and a variable deceleration parameter, showing strings dominate early universe and vanish over time, aligning with observations.

Contribution

It introduces a new class of cosmological models with variable deceleration parameter incorporating massive strings in Bianchi-I spacetime.

Findings

Massive strings dominate the early universe.

Strings disappear at large times, consistent with observations.

Models exhibit specific physical and geometrical behaviors.

Abstract

The present study deals with LRS Bianchi type I cosmological model representing massive string. The energy-momentum tensor for such string as formulated by Letelier (1983) is used to construct massive string cosmological models for which we assume that the shear scalar ($\sigma$) is proportional to the expansion scalar ($\theta$). The study reveals that massive strings dominate the early Universe. The strings eventually disappear from the Universe for sufficiently large time, which is in agreement with the current astronomical observations. Some physical and geometrical behaviour of models are also discussed.