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arXiv · 2311.03399

Perturbations in Bianchi Type-I spacetimes with varying Lambda, G

Alnadhief H. A. Alfedeel·Maye Elmardi·Amare abebe
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Abstract

In this paper, we investigate the evolution of cosmological perturbations within the context of Bianchi Type$-I$ spacetimes. We consider models containing viscous fluids with evolving cosmological (\LL) and Newtonian gravitational (G) parameters. The investigation of how over-densities in the viscous matter content in the Bianchi Type$-I$ model is our primary emphasis. In particular, we investigate the generation and propagation of signals associated with large-scale structures in this setting. We contrast our findings with the predictions of the classic $\Lambda$CDM ($\Lambda$-Cold-Dark-Matter) cosmological model to draw relevant contrasts and insights. Our findings emphasise the need to incorporate viscous fluids into the Bianchi Type$-I$ geometry, as well as the dynamic fluctuations of \LL and $G$. These factors influence the rate of structure growth in the cosmos as a whole. Thus, our findings offer light on the complex dynamic interaction between viscosity, changing cosmological parameters, and the growth of large-scale structures in an anisotropic universe.

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Alnadhief H. A. Alfedeel, Maye Elmardi, Amare abebe. 2023-11-05. Perturbations in Bianchi Type-I spacetimes with varying Lambda, G. https://arxiv.org/abs/2311.03399

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