Distinguishing between R2-inflation and Higgs-inflation

We present three features which can be used to distinguish the R-2-inflation Higgs-inflation from with ongoing, upcoming and planned experiments, assuming no new physics (apart form sterile neutrinos) up to inflationary scale. (i) Slightly different tilt of the scalar perturbation spectrum n(s) and ratio r of scalar-to-tensor perturbation amplitudes. (ii) Gravity waves produced within R-2-model by collapsing, merging and evaporating scalaron clumps formed in the post-inflationary Universe. (iii) Different ranges of the possible Standard Model Higgs boson masses, where the electroweak vacuum remains stable while the Universe evolves after inflation. Specifically, in the R-2-model Higgs boson can be as light as 116 GeV. These effects mainly rely on the lower reheating temperature in the R-2-inflation. Published by Elsevier B.V.