English

Does Palatini Higgs Inflation Conserve Unitarity?

High Energy Physics - Phenomenology 2021-05-05 v4 High Energy Physics - Theory

Abstract

In the conventional metric formulation of gravity, the Higgs Inflation model violates unitarity in the electroweak vacuum in Higgs scattering at the energy scale ΛMPl/ξ\Lambda \sim M_{Pl}/\xi, where ξ104\xi \sim 10^4 is the non-minimal coupling of the Higgs to the Ricci scalar. In the Palatini formulation it is commonly believed that ΛMPl/ξ\Lambda \sim M_{Pl}/\sqrt{\xi}, where ξ109\xi \sim 10^{9}. Here we reconsider unitarity violation in the electroweak vacuum in the Palatini formulation. We argue that there is no unitarity violation in Higgs scattering in the Palatini non-minimally coupled Standard Model in the electroweak vacuum at energies below the Planck scale. In this case Palatini Higgs Inflation completely conserves unitarity and is consistent at all energies up to those at which quantum gravity becomes important. If true, this would imply that Palatini Higgs Inflation has a significant advantage over metric Higgs Inflation.

Keywords

Cite

@article{arxiv.2007.04111,
  title  = {Does Palatini Higgs Inflation Conserve Unitarity?},
  author = {J. McDonald},
  journal= {arXiv preprint arXiv:2007.04111},
  year   = {2021}
}

Comments

8 pages. Additional reference. Published in JCAP

R2 v1 2026-06-23T16:57:04.506Z