Living beyond the edge: Higgs inflation and vacuum metastability

摘要

The measurements of the Higgs mass and top Yukawa coupling indicate that welive in a very special Universe, at the edge of the absolute stability of theelectroweak vacuum. If fully stable, the Standard Model (SM) can be extendedall the way up to the inflationary scale and the Higgs field, non-minimallycoupled to gravity with strength $\xi$, can be responsible for inflation. Weshow that the successful Higgs inflation scenario can also take place if the SMvacuum is not absolutely stable. This conclusion is based on two effects thatwere overlooked previously. The first one is associated with the effectiverenormalization of the SM couplings at the energy scale $M_P/\xi$, where $M_P$is the Planck scale. The second one is a symmetry restoration after inflationdue to high temperature effects that leads to the (temporary) disappearance ofthe vacuum at Planck values of the Higgs field.