Noncoincidence <i>f</i> ( <i>Q</i> )‐Cosmology with Dark Matter Coupled to Gravity

ABSTRACT We investigate Friedmann–Lemaître–Robertson–Walker (FLRW) cosmology in the framework of symmetric teleparallel gravity with a nonminimal coupling between dark matter and the gravitational field. In the noncoincidence gauge, the field equations admit an equivalent multi‐scalar field representation, which we investigate the phase‐space using the Hubble‐normalization approach. We classify all stationary points for arbitrary function and we discuss the physical properties of the asymptotic solutions. For the power‐law theory, we perform a detailed stability analysis and show that the de Sitter solution is the unique future attractor, while the matter‐dominated point appears as a saddle point. Moreover, there exist a family of scaling solutions that can be related to inflationary dynamics. In contrast with uncoupled models, the presence of the coupling introduces a viable matter‐dominated era alongside late‐time accelerated expansion. Our study shows that the coupling function plays a crucial role in cosmological dynamics in gravity.