Extended datasamples under the lens of Brane World Theory

TL;DR

This paper investigates a modified Randall-Sundrum Brane World model with redshift-dependent brane tension, testing its ability to explain cosmic acceleration without dark energy through Bayesian analysis of observational data.

Contribution

It introduces a novel exponential, redshift-dependent brane tension into the Randall-Sundrum model and assesses its viability against observational data without dark energy.

Findings

Reproduces late-time cosmic acceleration consistent with observations.

Finds agreement with LCDM at the transition redshift zt.

Detects a 'Big Rip' divergence at z=1 and highlights model sensitivities.

Abstract

This work revises the Brane World Theory known as Randall-Sundrum with the modification of an exponential, redshift-dependent brane tension. This model is studied in a scenario assuming no dark energy, with the aim of determining whether it can reproduce the universe's acceleration on its own, without the addition of a dark energy fluid. Bayesian statistical analysis is performed in order to constrain the free parameters of each scenario using SLS, SNIa, OHD, and BAO data samples, the last two considering newly added data points. Both Planck and Riess priors for h are used and compared. In both cases, we are able to reproduce the late-time accelerated expansion in agreement with observational data. Interesting consistencies at the transition redshift zt with LCDM are found, suggesting that this might be a suitable model for studying the evolution of the universe up to the present date. However, some pathologies are detected in this model, namely a "Big Rip" divergence of H(z) at z = 1, as well as a strong dependence between the functional form of the brane tension and the future evolution of the universe.