# Constraining f(T) teleparallel gravity by Big Bang Nucleosynthesis

## TL;DR

This paper uses Big Bang Nucleosynthesis data to constrain three popular f(T) gravity models, finding that they can satisfy early universe bounds and are consistent with late-time cosmological data.

## Contribution

It provides the first comprehensive BBN-based constraints on power-law, exponential, and square-root exponential f(T) gravity models, confirming their viability.

## Key findings

- Power-law model constraints align with late-time data.
- Exponential models satisfy BBN bounds within certain parameter regions.
- Viable f(T) models can meet early universe nucleosynthesis constraints.

## Abstract

We use BBN observational data on primordial abundance of ${}^4He$ to constrain f(T) gravity. The three most studied viable $f(T)$ models, namely the power law, the exponential and the square-root exponential are considered, and the BBN bounds are adopted in order to extract constraints on their free parameters. For the power-law model, we find that the constraints are in agreement with those acquired using late-time cosmological data. For the exponential and the square-root exponential models, we show that for realiable regions of parameters space they always satisfy the BBN bounds. We conclude that viable f(T) models can successfully satisfy the BBN constraints.