Non-Abelian Einstein-Born-Infeld-dilaton cosmology

The non-Abelian Einstein-Born-Infeld-dilaton theory, which rules the dynamics of tensor-scalar gravitation coupled to a $su(2)$-valued gauge field ruled by Born-Infeld Lagrangian, is studied in a cosmological framework. The microscopic energy exchange between the gauge field and the dilaton which results from a nonuniversality of the coupling to gravity modifies the usual behavior of tensor-scalar theories coupled to matter fluids. General cosmological evolutions are derived for different couplings to gravitation and a comparison to universal coupling is highlighted. Evidences of cosmic acceleration are presented when the evolution is interpreted in the Jordan physical frame of a matter respecting the weak equivalence principle. The importance for the mechanism of cosmic acceleration of the dynamics of the Born-Infeld gauge field, the attraction role of the matter fluid, and the nonuniversality of the gravitational couplings are briefly outlined.