Speaker
Description
The Standard Model Higgs field can play an essential role in the very early Universe to realize the cosmic inflation, providing proper initial conditions for the hot big bang theory. However, the vanilla Higgs inflation model suffers from the unitarity problem when the Higgs field decays into gauge bosons after inflation, as the momentum of the produced gauge bosons can be higher than the UV cutoff of the model. Such inconsistency can be resolved by considering the UV extended Higgs inflation with an $R^2$ operator. In this talk, I will introduce a new geometric method to unambiguously determine the cutoff scale of general nonlinear sigma models, including the Higgs inflation, and discuss the unitarity problem of the Higgs inflation. I will show that the $R^2$ corrected model, namely the mixed Higgs-$R^2$ inflation, is free from such problem up to Planck scale and has rich phenomenology during reheating.
| Session Selection | Particle and Nuclear Physics |
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