2025/09/24 by Cruz, Daniel F. P., Pereira, David S., Lobo, Francisco S. N. +1
#Cosmology and Nongalactic Astrophysics (astro-ph.CO) #FOS: Physical sciences #General Relativity and Quantum Cosmology (gr-qc) #High Energy Physics - Theory (hep-th)
paper · doi:10.48550/arxiv.2509.20309
In this work, we investigate Big Bang Nucleosynthesis (BBN) within the framework of f(T,Lm) gravity, where the gravitational Lagrangian is generalized as a function of the torsion scalar T and the matter Lagrangian Lm. We analyze three representative f(T,Lm) models and derive constraints on their free parameters, α and β, by combining observational bounds from the freeze-out temperature with the primordial abundances of deuterium, helium-4, and lithium-7. For each model, the parameter space consistent with all elemental Z-constraints and the freeze-out condition is determined. These results demonstrate that f(T,Lm) modifications can accommodate the tight observational constraints of BBN, suggesting that minimal extensions to the matter sector provide viable alternatives to the standard cosmological description and offer a promising framework for exploring modified gravity in the early Universe.