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arXiv · 2504.04502

Cosmological Singularities in Brane Gravity

R. Jalalzadeh·S. Jalalzadeh·Y. Heydarzade
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Abstract

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.

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R. Jalalzadeh, S. Jalalzadeh, Y. Heydarzade. 2025-04-06. Cosmological Singularities in Brane Gravity. https://doi.org/10.1016/j.nuclphysb.2025.116945

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