TH BSM Forum

Higgs inflation, unitarity, and emergence of scalaron

by Yohei Ema (Deutsches Elektronen-Synchrotron DESY)

4/3-006 - TH Conference Room (CERN)

4/3-006 - TH Conference Room


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Higgs inflation introduces a large non-minimal coupling between the Ricci scalar and Higgs that makes the cut-off scale well below the Planck scale. In the first part of the talk, we show that unitarity is indeed violated by a resonant production of longitudinal gauge bosons after inflation, calling for UV completion of Higgs inflation. We then show that unitarity is restored after summing over vacuum polarization-type diagrams that are leading-order in the large-N limit. Scattering amplitude develops a pole after the resummation, which we identify as the scalar component of the metric, or the scalaron. This phenomenon can be understood in the language of the non-linear sigma model (NLSM), with the scalaron identified as the sigma-meson that linearizes the NLSM.

BSM Forum
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Elena Gianolio
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Matthew Philip Mccullough, Daniele Teresi, Joachim Kopp, Benoit Loyer, Nicholas Llewellyn Rodd
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