Cosmic structure growth and perturbation analysis in logarithmic f(Q) gravity

In this work, we explore a cosmological model within the framework of modified gravity, specifically a logarithmic form of f ( Q ) gravity. Using recent observational datasets including RSD and DESI, we constrain the model parameters via Markov Chain Monte Carlo (MCMC) techniques. Our analysis focuses on both background and perturbation-level cosmological diagnostics, evaluating the evolution of cosmographic parameters and the growth rate of structure through fσ ₈ f σ 8 . The results demonstrate consistency with observational data, particularly supporting a quintessence-like accelerated expansion. Additionally, the model addresses the S₈ S 8 tension and provides insights into the late-time behavior of dark energy.