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arXiv · 2510.00535

Noncoincidence $f(Q)$-Cosmology with Dark Matter Coupled to Gravity

A. Abebe·P. S. Apostolopoulos·A. Giacomini·G. Leon·F. Moncada·A. Paliathanasis
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Abstract

We investigate FLRW cosmology in the framework of symmetric teleparallel $f(Q)$ 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 $f(Q)$ 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 $f(Q)$ 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 $f(Q)$ gravity.

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A. Abebe, P. S. Apostolopoulos, A. Giacomini, G. Leon, F. Moncada, A. Paliathanasis. 2025-10-01. Noncoincidence $f(Q)$-Cosmology with Dark Matter Coupled to Gravity. https://arxiv.org/abs/2510.00535

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