Loop inflection-point inflation

A novel inflection-point inflation model is analysed. The model considers a massless scalar field, whose self-coupling's running is stabilised by a non-renormalisable operator. The running is controlled by a fermion loop. We find that successful inflation is possible for a natural value of the Yukawa coupling y≃4×10−4. The necessary fine-tuning is only ∼10−6, which improves on the typical tuning of inflection-point inflation models, such as MSSM inflation. The model predicts a spectral index within the 1-σ bound of the latest CMB observations, with a very small negative running, and negligible tensors (r∼10−(9−10)). These results are largely independent of the order of the stabilising non-renormalisable operator.