Speaker
Description
The Higgs non-minimal coupling to background curvature is well known to stabilise Higgs fluctuations during inflation, thus alleviating the vacuum-stability problem. However, during a post-inflationary phase of kination, the same coupling can generate a large tachyonic effective mass, dramatically worsening the stability of the Higgs vacuum. In this talk, I will show how this tachyonic instability leads to a minimal scenario of reheating through the intense non-perturbative production of Higgs quanta. Reheating proceeds entirely within the Standard Model sector, while generating a characteristic gravitational-wave signal that carries information about the Higgs effective potential at high energy scales. I will also discuss the conditions under which vacuum stability is maintained across a broad parameter space, highlighting its dependence on the precise value of the top-quark pole mass.