Modified Takabayasi String in Bulk Viscous Bianchi Type-III Cosmology: Dynamics in the Presence of Variable Λ

Abstract

In the current work, the solutions for Bianchi type III cosmolog- ical models in the presence of bulk viscous fluid are derived using a modified Takabayasi string of the form ρ = (1 + ω) λ + Λ. In order to achieve a realistic model, we make the assumption that there is a relationship between the metric potential, denoted as X₂, and another variable, denoted as X₃, raised to the power of n. We examined the significance of the Λ word in the cosmic evolution. In this study, we examined two distinct scenarios for the cosmological model, namely case i) where ω tends towards infinity, and case ii) where ω tends towards zero. In both situations, we have determined the physical meaning of the cosmological term Λ in a quadratic form, specifically Λ = Λ₀ + Λ₁H + Λ₂H². The physical and geometrical components of the model are thoroughly examined for both scenarios, and their as- sociated solutions are discussed. It has been noted that the resulting models align with current findings and literature that support the idea of the universe’s acceleration. In addition, we have generated diagrams to facilitate a comprehensive analysis of each individual scenario.