Inflation models in the light of self-interacting sterile neutrinos

Short baseline neutrino experiments, like Liquid Scintillator Neutrino Detector and MiniBooNE experiments, pointed toward the existence of eV mass scale sterile neutrinos. To reconcile sterile neutrinos with cosmology self-interaction between sterile neutrinos has been studied. We analyzed Planck cosmic microwave background (CMB) data with self-interacting sterile neutrino (SIν) and studied their impact on inflation models. The fit to the CMB data in SIν model is as good as the fit to ΛCDM model. We find that the spectral index (ns) values shift to 0.9361±0.0055 in SIν model. This has a significant impact on the validity of different inflation models. For example, the Starobinsky and quartic hilltop model, which were allowed within ΛCDM cosmology, are ruled out. On the other hand, some models like natural and Coleman-Weinberg inflation are now favored. Therefore, the existence of self-interacting sterile neutrinos with eV order of mass will play an important role in the selection of correct inflation model.