Cosmological Dynamics of a Novel f(Q) Gravity Model in light of DESI DR2 Observations

In this article, we investigate the cosmological viability of a modified symmetric teleparallel gravity model within the f(Q) framework. We derive observational constraints on the model parameters by performing a Markov Chain Monte Carlo analysis using a combined dataset consisting of cosmic chronometers, PantheonPlus SH0ES, and DESI BAO DR2. Our analysis yields the best-fit values for the model parameters m = −0.386 ± 0.090 and n = −1.055 ± 0.047, along with the cosmological parameters at present: H0 = 73.19 ± 0.25, q0 = −0.51 ± 0.6, and ω0 = −0.73 ± 0.3, at 68% CL. Furthermore, we examine the physical behavior of the model, focusing on the effective equation of state and deceleration parameter. Our findings indicate that the model experiences a transition from the early deceleration phase to the late-time cosmic acceleration, and the transition occurs at a redshift ztr = 0.573. We also analyse the om(z) diagnostic, which reflects a positive slope, supporting the behavior of the equation of state parameter in the quintessence region.