Data-driven Reconstruction of the Late-time Cosmic Acceleration with f(T) Gravity

TL;DR

This paper reconstructs the f(T) gravity function using observational data, revealing a small oscillatory deviation from the standard DM model, which could help resolve tensions in cosmological measurements.

Contribution

It introduces a novel, model-independent reconstruction of f(T) gravity from data, proposing an oscillatory form that aligns with observations and extends previous dark energy models.

Findings

Reconstructed f(T) function is consistent with DM within 1C confidence level.

Identified a small sinusoidal oscillation in the best-fit f(T) form.

Oscillatory f(T) model may alleviate tensions in H0 and  estimations.

Abstract

We use a combination of observational data in order to reconstruct the free function of f(T) gravity in a model-independent manner. Starting from the data-driven determined dark-energy equation-of-state parameter we are able to reconstruct the f(T) form. The obtained function is consistent with the standard {\Lambda}CDM cosmology within 1{\sigma} confidence level, however the best-fit value experiences oscillatory features. We parametrise it with a sinusoidal function with only one extra parameter comparing to {\Lambda}CDM paradigm, which is a small oscillatory deviation from it, close to the best-fit curve, and inside the 1{\sigma} reconstructed region. Similar oscillatory dark-energy scenarios are known to be in good agreement with observational data, nevertheless this is the first time that such a behavior is proposed for f(T) gravity. Finally, since the reconstruction procedure is completely model-independent, the obtained data-driven reconstructed f(T) form could release the tensions between {\Lambda}CDM estimations and local measurements, such as the H0 and {\sigma}8 ones.