Cosmology of f(Q,L_m) gravity with Holographic Ricci Dark Energy: Early-Time Inflation and Late-Time Acceleration and RGUP Corrected Observables
This study investigates a cosmological scenario within the f(Q,L_m) gravity framework to explore whether one geometric model can simultaneously describe the early and late-time accelerated epochs. Motivated by the recently proposed f(Q,L_m) gravity framework by Hazarika et al. [Phys. Dark Universe 50 (2025) 102092], we adopt a minimal polynomial form, f(Q,L_m) = -Q + alpha Q^2 + 2L_m + beta QL_m, and the late-time dynamics are reconstructed by introducing Holographic Ricci Dark Energy (HRDE) as an effective fluid. The resulting background evolution demonstrates smooth accelerated expansion, stable Hubble parameter behavior, and an effective equation of state that approaches the de Sitter regime. Bayesian analysis utilizing Pantheon supernovae, cosmic chronometer, and DESI BAO data reveals that the matter-geometry coupling parameter beta is weakly constrained and remains consistent with the LambdaCDM limit. In the high-curvature regime characteristic of the early Universe, the quadratic non-metricity term alpha Q^2 dominates the dynamics, resulting in a Starobinsky-like inflationary phase driven solely by geometric effects with predicted n_s and r values consistent with Planck 2018 observations. Furthermore, quantum-gravity-inspired corrections are examined through a Relativistic Generalized Uncertainty Principle (RGUP), implemented as a momentum-dependent deformation of the effective spacetime metric. These corrections maintain the geometric inflationary background while introducing minor perturbative shifts in higher-order inflationary observables, specifically the running of the spectral index. Overall, these findings indicate that the f(Q,L_m) framework offers a dynamically consistent geometric model in which early and late cosmic acceleration arise from distinct curvature regimes, with RGUP effects causing sub-leading modifications.