Locally Rotationally Symmetric Bianchi Type-II Magnetized String Cosmological Model with Bulk Viscous Fluid in General Relativity

Abstract

The locally rotationally symmetric Bianchi type-II magnetized string cosmological model with bulk viscous fluid is investigated. The magnetic field is due to an electric current produced along the 𝑥-axis. Thus the magnetic field is in the 𝑦-𝑧 plane and 𝐹23 is the only non-vanishing component of electromagnetic field tensor 𝐹𝑖𝑗. To obtain the deterministic model in terms of cosmic time 𝑡, we have assumed the condition 𝜉𝜃=const, where 𝜉 is the coefficient of bulk viscosity and 𝜃 is the expansion in the model.

Dynamics of Magnetized Bulk Viscous Strings in Brans–dicke Gravity

“…However, in the present work, no such ambiguity exists and the results are in well agreement with the observations. It is worthwhile to mention here that our results are consistent with those already available in the context of GR [27].…”

“…In this section, we discuss BI model with electromagnetic bulk viscous cloud of strings as background fluid distribution given by the energy-momentum tensor [27] T…”

“…• Also, we take ξΘ = M 1 , by setting the expansion scalar inversely proportional to bulk viscosity coefficient [27] which means that the rate of cosmic expansion decreases as the viscosity increases. Here M 1 is any positive constant.…”

“…The study of magnetic field effects in the matter distribution is of considerable interest as it provides an effective way to understand the initial phases of cosmic evolution. Bulk viscous effects in the fluid lead to negative energy field and hence have a significant impact on the dynamics of the universe [26,27]. Thus the study of magnetized cosmic stings under the influence of bulk viscosity leads to a better understanding of the dynamics of the universe.…”

Evolution of Bianchi I magnetized cosmic strings in Brans–Dicke gravity

“…Cosmic strings can interact with gravity and hence yield many significant astrophysical and gravitational consequences. Since viscous effects, being a negative energy field, can act as a source of DE, hence providing a better description of dynamics of the universe (Misner 1968, Tyagi andSharma 2011). Moreover, it is argued that the magnetic field has a cosmic origin and thus it is helpful for understanding the early epochs of the universe.…”