Cyclic universe from uniform rate inflation on the brane with a timelike extra dimension

Fuente: arXiv
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Autores principales: Sengupta, Rikpratik, Aich, Arkajit, Bhattacharya, Kaushik
Formato: Preprint
Publicado: 2026
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author Sengupta, Rikpratik
Aich, Arkajit
Bhattacharya, Kaushik
author_facet Sengupta, Rikpratik
Aich, Arkajit
Bhattacharya, Kaushik
contents We investigate a non-singular cosmological scenario in which uniform-rate inflation is realised on an anisotropic Shtanov-Sahni braneworld. The model naturally resolves the initial singularity resulting in an infinite number of smooth non-singular bounces, while accommodating a phase of accelerated expansion driven by a scalar field rolling at a constant rate. The presence of a timelike extra dimension induces high-energy corrections to the effective Friedmann dynamics, allowing anisotropic shear to be dynamically suppressed near the bounce and rendering the background evolution stable. We derive the full background dynamics analytically and demonstrate that uniform-rate inflation can be consistently embedded within an anisotropic braneworld framework. Primordial scalar and tensor perturbations are analysed using the $δN$ formalism, ensuring that only physically relevant modes exiting the horizon during inflation contribute to observable quantities. Remarkably, we find that observational consistency can be achieved with different levels of anisotropy in the two different scenarios we consider, without compromising the smoothness or stability of the bounce. Our results establish uniform-rate inflation on an anisotropic braneworld as a robust and observationally viable alternative to standard inflationary cosmology, offering a compelling framework in which non-singular early-universe dynamics and precision cosmology can be consistently unified.
format Preprint
id arxiv_https___arxiv_org_abs_2602_08974
institution arXiv
publishDate 2026
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spellingShingle Cyclic universe from uniform rate inflation on the brane with a timelike extra dimension
Sengupta, Rikpratik
Aich, Arkajit
Bhattacharya, Kaushik
General Relativity and Quantum Cosmology
We investigate a non-singular cosmological scenario in which uniform-rate inflation is realised on an anisotropic Shtanov-Sahni braneworld. The model naturally resolves the initial singularity resulting in an infinite number of smooth non-singular bounces, while accommodating a phase of accelerated expansion driven by a scalar field rolling at a constant rate. The presence of a timelike extra dimension induces high-energy corrections to the effective Friedmann dynamics, allowing anisotropic shear to be dynamically suppressed near the bounce and rendering the background evolution stable. We derive the full background dynamics analytically and demonstrate that uniform-rate inflation can be consistently embedded within an anisotropic braneworld framework. Primordial scalar and tensor perturbations are analysed using the $δN$ formalism, ensuring that only physically relevant modes exiting the horizon during inflation contribute to observable quantities. Remarkably, we find that observational consistency can be achieved with different levels of anisotropy in the two different scenarios we consider, without compromising the smoothness or stability of the bounce. Our results establish uniform-rate inflation on an anisotropic braneworld as a robust and observationally viable alternative to standard inflationary cosmology, offering a compelling framework in which non-singular early-universe dynamics and precision cosmology can be consistently unified.
title Cyclic universe from uniform rate inflation on the brane with a timelike extra dimension
topic General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2602.08974