Extended teleparallel gravity, characterized by functionF(Q), whereQis the non-metricity scalar, is one of the most promising approaches to general relativity. In this paper, we reexamine a specific dynamical dark energy model, which is indistinguishable from the $$\Lambda $$Λ CDM model at the present time and exhibits a special event in the future, withinF(Q) gravity. To constrain the free parameters of the model, we perform Markov chain Monte Carlo (MCMC) analysis, using the last data from $$\hbox {Pantheon}^{+}$$Pantheon+ and the latest measurements of the H(z) parameter, combined. On the basis of this analysis, we find that our dynamical dark energy model, in the context of F(Q) gravity, lies in the quintessence regime rather than in the phantom regime, as in the case of general relativity. Furthermore, this behavior affects the future expansion of the Universe, as it becomes decelerating at a $$1\sigma $$1σ confidence level for $$z<-0.5$$z<-0.5 , showing a bounce at $$z_{\text {B}}\approx -0.835$$zB≈-0.835 . We support our conclusion with a cosmographic analysis.

In this paper, we explore one of Einstein’s alternative formulations which involves the non-metricity scalar, Q, within the framework of f(Q) theory. Our study focuses on solving the modified Friedmann equations for the case of dust matter, $$\rho =\rho _{m}$$ρ = ρ m , and a form of $$f(Q) = \alpha + \beta Q^n$$f ( Q ) = α + β Q n . We investigate the behavior of our model in both linear $$(n=1)$$( n = 1 ) and nonlinear $$(n\ne 1)$$( n ≠ 1 ) scenarios at the background and perturbation levels. By employing the Markov chain Monte Carlo (MCMC) method, we constrain our model using observational datasets including redshift space distortion, cosmic chronometers, and Pantheon $$^+$$+ . Without using any parameterization of the growth rate index which quantifies the deviation from the $$\Lambda $$Λ CDM model, both models exhibit good accuracy in describing the redshift space distortion. We further analyze the dynamics of the Universe using cosmography parameters, where our model exhibits a phase transition between deceleration and acceleration phases at $$z=0.789$$z = 0.789 . Our findings reveal that our model exhibits a phantom-like behavior based on statefinder diagnostic analysis. Interestingly, the model demonstrates a rich variety of behaviors, resembling either a quintessence-like scenario for $$(n<1)$$( n < 1 ) or phantom-like scenario for $$(n\ge 1)$$( n ≥ 1 ) . Using the MCMC best fit and parameterizing the growth index, the evolution of the growth index also depends on the parameter n, either remaining constant (in the linear case) or showing a decreasing trend (in the nonlinear case), indicating a weaker growth rate of density perturbations during earlier cosmic times. Finally, we compare our findings of the growth index with the values obtained in the literature.