Weak-scale Higgs inflation

The present measurement of the Standard Model (SM) parameters suggests that the Higgs effective potential has a maximum at the Higgs field value of approximately 1011GeV, and the electroweak (EW) vacuum is not absolutely stable. To achieve absolute EW stability, a very large Higgs-Ricci scalar non-minimal coupling can be introduced. I study cosmic inflation driven by the Higgs field in this extension of the SM and refer to it as “weak-scale Higgs inflation” because the resulting inflationary Hubble parameter is around the weak scale. The Palatini formulation of gravity with a dimension 6 term is shown to drive successful inflation. I also argue for the UV (in)sensitivity of the predictions, and phenomenological implications. In the metric formulation case, the scenario for stable EW vacuum may be probed by measuring the Higgs coupling in future colliders.