Phase space analysis of cosmological models on f ( R,G,T ) gravity

We investigate the cosmological dynamics of a modified gravity theory described by [Formula: see text], where [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] are the free parameters. By introducing appropriate dimensionless variables, the field equations are reformulated as an autonomous system of ordinary differential equations, enabling a dynamical systems analysis. We identify eight critical points and examine their stability, then we determine the conditions under which a late-time accelerated expansion arises as a stable attractor. For our model, we obtain [Formula: see text] stable attractors. The model yields a transition redshift at [Formula: see text], present-day deceleration parameter [Formula: see text], and equation of state parameter [Formula: see text], which are all consistent with current observational bounds. The evolution of density parameters as a function of [Formula: see text] indicates a Universe presently dominated by dark energy. Additional diagnostics, including the state finder parameters, are employed to characterise the cosmic phases corresponding to the critical points. Finally, a combined analysis using 77 Hubble, 15 BAO, and 1048 Pantheon data demonstrates that the model closely reproduces the behaviour of the [Formula: see text]CDM paradigm.