Modified cosmology in $f(Q,L_m)$ gravity

Abstract

In this letter, we investigate cosmology within the framework of modified $f(Q,L_m)$ gravity using the non-linear model $f(Q,L_m)=-Q+\hat{I}\pm L_m^n+{\hat{I}}^2$, where $\hat{I}\pm$, ${\hat{I}}^2$, and $n$ are free parameters. The modified Friedmann equations are derived for a matter-dominated universe, and an analytical solution is obtained. Using Hubble, Pantheon+, and joint datasets, we constrain the model parameters and examine their implications. The results indicate that the model accommodates varying $H_0$ values, contributing to the Hubble tension, while $n\ne 1$ suggests deviations from general relativity (GR). The deceleration parameter confirms a transition to acceleration at $z_t\approx 0.6-0.8$, with present values supporting cosmic acceleration. This model offers a viable alternative to GR-based cosmology.

Physics Letters B published version