UV (in)sensitivity of Higgs inflation

TL;DR

This paper investigates the robustness of Higgs inflation predictions against unknown high-energy physics effects, finding that inflationary observables are largely insensitive to UV threshold corrections due to a precise cancellation.

Contribution

It demonstrates that Higgs inflation predictions are stable against UV threshold corrections, indicating limited ability to probe UV physics through CMB parameters.

Findings

Inflationary predictions are unaffected by UV threshold corrections.

CMB parameters cannot be used to infer UV physics effects.

Spectral index and tensor-to-scalar ratio are insensitive to top and Higgs mass variations.

Abstract

The predictions of Standard Model Higgs inflation are in excellent agreement with the Planck data, without the need for new fields. However, consistency of the theory requires the presence of (unknown) threshold corrections. These modify the running of the couplings, and thereby change the shape of the inflationary potential. This raises the question how sensitive the CMB parameters are to the UV completion. We show that, due to a precise cancellation, the inflationary predictions are almost unaffected. This implies in general that one cannot relate the spectral index and tensor-to-scalar ratio to the precise top and Higgs mass measurements at the LHC, nor can one probe effects of UV physics on the running.