CASTING LIGHT ON THE GHOST

Abstract

The infrared sector of QCD contains all the necessary ingredients, once laid onto a time-dependent, curved background, to cater for the much needed cosmological vacuum energy. This is achieved through the fields that describe the impact of the long-range interactions of QCD, the Veneziano ghost and its dipolar partner. Although technically extremely challenging, the physics is well understood and the estimated dark energy density is of the correct order of magnitude. In this brief review I will retrace the steps leading to two new cosmological applications of this model, namely the possibility of the generation of cosmic magnetic fields, and the unification of several observed polarization anomalies under the same roof.