Late-time cosmology in f(Q, L_m) gravity: Analytical solutions and observational fits

Abstract

In this study, we examined the late-time cosmic expansion of the universe within the framework of gravity, where denotes the non-metricity and represents the matter Lagrangian. We analyzed a linear model of the form . Using MCMC methods, we constrained the model parameters , , and with various datasets, including , Pantheon+SH0ES, and BAO data. For the dataset, we found , , and . For the Pantheon+SH0ES dataset, , , and . For the BAO dataset, , , and . Moreover, the energy density remains positive and approaches zero in the distant future, and the deceleration parameter indicates a transition from deceleration to acceleration, with transition redshifts of , , and for the respective datasets. These findings align with previous observational studies and contribute to our understanding of the universe's expansion dynamics.