Running inflation in the Standard Model

Abstract

An interacting scalar field with largish coupling to curvature can support a\ndistinctive inflationary universe scenario. Previously this has been discussed\nfor the Standard Model Higgs field, treated classically or in a leading log\napproximation. Here we investigate the quantum theory using renormalization\ngroup methods. In this model the running of both the effective Planck mass and\nthe couplings is important. The cosmological predictions are consistent with\nexisting WMAP5 data, with 0.967 < n_s < 0.98 (for N_e = 60) and negligible\ngravity waves. We find a relationship between the spectral index and the Higgs\nmass that is sharply varying for m_h ~ 120-135 GeV (depending on the top mass);\nin the future, that relationship could be tested against data from PLANCK and\nLHC. We also comment briefly on how similar dynamics might arise in more\ngeneral settings, and discuss our assumptions from the effective field theory\npoint of view.\n