Quantum effects in Palatini Higgs inflation
Abstract
We study quantum effects in Higgs inflation in the Palatini formulation of gravity, in which the metric and connection are treated as independent variables. We exploit the fact that the cutoff, above which perturbation theory breaks down, is higher than the scale of inflation. Unless new physics above the cutoff leads to unnaturally large corrections, we can directly connect low-energy physics and inflation. On the one hand, the lower bound on the top Yukawa coupling due to collider experiments leads to an upper bound on the non-minimal coupling of the Higgs field to gravity: ξ lesssim 108. On the other hand, the Higgs potential can only support successful inflation if ξ gtrsim 106. This leads to a fairly strict upper bound on the top Yukawa coupling of 0.925 (defined in the bar Mbar S-scheme at the energy scale 173.2 GeV) and constrains the inflationary prediction for the tensor-to-scalar ratio. Additionally, we compare our findings to metric Higgs inflation.
- Publication:
-
Journal of Cosmology and Astroparticle Physics
- Pub Date:
- July 2020
- DOI:
- 10.1088/1475-7516/2020/07/064
- arXiv:
- arXiv:2002.07105
- Bibcode:
- 2020JCAP...07..064S
- Keywords:
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- High Energy Physics - Phenomenology;
- Astrophysics - Cosmology and Nongalactic Astrophysics;
- General Relativity and Quantum Cosmology;
- High Energy Physics - Theory
- E-Print:
- 20 pages, 2 figures