This paper is available on arxiv under CC 4.0 license.
Authors:
(1) A. Oliveros, Programa de F´ısica, Universidad del Atl´antico;
(2) Mario A. Acero, Programa de F´ısica, Universidad del Atl´antico.
In general, the action for an f(Q) gravity model in the presence of matter components is given by
with the Levi-Civita connection of the metric given by
the contortion tensor is
Considering the flat Friedman-Robertson-Walker (FRW) metric,
with a(t) representing the scale factor, the time and spatial components of Eq. (10) are given, respectively, by [9, 10]
and
It should be noted that in this scenario, the standard Friedmann equations of General Relativity (GR) plus the cosmological constant are recovered when assuming that f(Q) = Q + 2Λ.
If there is no interaction between non-relativistic matter and radiation, then these components obey separately the conservation laws
As usual in the literature, it is possible to rewrite the field equations (13) and (14) in the Einstein-Hilbert form:
In this case, we assume that the equation of state parameter for this effective dark energy satisfies the following relation: