Running inflation with unitary Higgs

We consider the renormalization group (RG) improved inflaton potential in unitarized Higgs inflation where the original Higgs inflation is unitarized by the addition of a real singlet scalar of sigma-model type. The sigma-field coupling to the Higgs, which is introduced to reproduce a large non-minimal coupling of the Higgs below the sigma scalar threshold, also improves the Standard Model vacuum stability due to the RG running. Furthermore, the same sigma-field coupling determines the reheating temperature or the number of efoldings. Considering the uncertainties in the number of efoldings in the model, we show that the loop-corrected spectral index and tensor-to-scalar ratio are consistent with nine-year WMAP and new Planck data within 1σ.