Cosmological singularities in brane gravity

We present a comprehensive study of cosmological singularities within the framework of Covariant Extrinsic Gravity (CEG), addressing both the initial Big Bang singularity and potential finite-time future singularities. Through detailed analysis of the emergent universe scenario, we systematically ex...

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Bibliographic Details
Main Authors: R. Jalalzadeh, S. Jalalzadeh, Y. Heydarzade
Format: Article
Language:English
Published: Elsevier 2025-08-01
Series:Nuclear Physics B
Online Access:http://www.sciencedirect.com/science/article/pii/S0550321325001543
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Summary:We present a comprehensive study of cosmological singularities within the framework of Covariant Extrinsic Gravity (CEG), addressing both the initial Big Bang singularity and potential finite-time future singularities. Through detailed analysis of the emergent universe scenario, we systematically examine homogeneous and inhomogeneous perturbations (encompassing scalar, vector, and tensor modes) in a 4D FLRW brane geometry. Our work establishes rigorous existence criteria and stability conditions for a nonsingular Einstein static initial state, demonstrating that such a configuration remains stable for well-defined parameter ranges in CEG – thereby providing a compelling resolution to the long-standing initial singularity problem. Extending our analysis to late-time cosmology, we perform a complete classification of future singularity types following Barrow et al.'s formalism, deriving precise conditions that determine whether the universe in CEG evolves toward or avoids these singular states.
ISSN:0550-3213