Abstract:
An intriguing and economical possibility to explain many cosmological observations is Higgs inflation, in which inflation is driven by the Standard Model Higgs with a non-minimal coupling to gravity. I will discuss near-critical Higgs inflation at two loops and show that, for any set of parameters derived from SM couplings at the electroweak scale and run to the inflationary scale, one can find a value of the non-minimal coupling that brings the model into compliance with all measured CMB observables. Unlike standard Higgs inflation, which typically requires unnaturally large values of the non-minimal coupling, I will demonstrate that in metric gravity we can match the CMB while staying within 3σ of electroweak precision data with non-minimal couplings on the order of 50–200. The success of the model, however, comes at the cost of self-consistency when it is treated as an effective description of electroweak-scale physics; that is, the model becomes unavoidably sensitive to physics beyond the SM in the UV, undermining the simplicity that originally motivated Higgs inflation.
