Cosmological Aspects of Multifield NMSSM Higgs Inflation

The inflationary NMSSM model(Next-to-Supersymmetric Standard Model) is considered to be the simplest extension to the Standard Model circumventing the mu-problem of the MSSM and thus being capable of giving inflation. As the MSSM model, it consists of two Higgs doublets and is augmented by one Higgs Singlet which is stabilized in Kähler moduli space. Research to date has focused on an effective single field description which in turn limits the range of possibilities for cosmological Observables and particle phenomenology. We have discovered that the previously assumed effective single field model can be described by an effective two-field model. The analysis has shown, that a clear distinction between single- and multi-field model can be made based on cosmological Observables that are constrained by Planck data leading to richer phenomenology.