Statistical Anisotropy and the Vector Curvaton Paradigm
  The vector curvaton paradigm is reviewed. The mechanism allows a massive
vector boson field to contribute to or even generate the curvature perturbation
in the Universe. Contribution of vector bosons is likely to generate
statistical anisotropy in the spectrum and bispectrum of the curvature
perturbation, which will soon be probed observationally. Two specific models
for the generation of superhorizon spectra for the components of an Abelian
vector field are analysed. Emphasis is put on the observational signatures of
the models when the vector fields play the role of vector curvatons. If future
observations support the vector curvaton mechanism this will open a window into
the gauge field content of theories beyond the standard model.
