Abstract
Big Bang Nucleosynthesis provides a powerful probe for understanding how light elements like lithium, helium, and deuterium are formed. In this work, we investigate how the freeze-out conditions during Big Bang Nucleosynthesis can be impacted by small deviations from the standard expansion of the universe, which are represented by the parameters [Formula: see text] and [Formula: see text], where [Formula: see text] and [Formula: see text] characterize torsion-matter corrections in the modified gravitational sector. The temperature and epoch at which nuclear reactions cease to be effective are influenced by these characteristics, which also alter the Hubble expansion rate. We examine the effects of these modifications on the anticipated abundances of 7 Li (lithium-7), 4 He (helium-4) and 2 H (deuterium) for three [Formula: see text] gravity models by using extended Einstein–Bose condensation matter. We identify permitted ranges of [Formula: see text] and [Formula: see text] that are still consistent with cosmological data by contrasting theoretical predictions with observed values. Our findings demonstrate that these parameters are strongly constrained by each element, resulting in highly constrained regions of parameter space. Due to its sensitivity to the neutron–proton ratio, helium offers the strictest constraint among them, while lithium and deuterium provide complementary constraints.