Observational constraints on complex quintessence with attractive self-interaction

In this paper, we consider that dark energy could be described solely by a complex scalar field with a Bose-Einstein condensate-like potential (denoted as CSFDE), that is, with a self-interaction and a mass term. In particular, we analyse a solution that in a fast oscillation regime at late times behaves as a cosmological constant. Our proposal adequately describes the standard homogeneous and flat Fridman dynamics. Furthermore, in this quintessence-complex scalar field scenario, it is possible to mimic the dynamics related to dark energy. However, when the precision cosmological tests are implemented in this landscape, the generic equation of state derived for this model in a restricted regime of a(i) (which corresponds to the scale factor at which the scalar field turns on) cannot be constrained by late-time current observations, since the analysis constraints solely the scalar field parameters within values ruled out by the theoretical model. This result is a clear hint to consider future CSFDE models with, for instance, two scalar fields in order to study the early-time dynamics of the Universe.

Automated summary

The paper suggests a model using a complex scalar field to describe dark energy dynamics, which can mimic the behavior of dark energy. However, when applied to current observations, there are constraints that may require further research into alternative models.