# Higgs inflation, unitarity, and emergence of scalaron

### APA

Ema, Y. (2022). Higgs inflation, unitarity, and emergence of scalaron. Perimeter Institute. https://pirsa.org/22010093

### MLA

Ema, Yohei. Higgs inflation, unitarity, and emergence of scalaron. Perimeter Institute, Jan. 25, 2022, https://pirsa.org/22010093

### BibTex

@misc{ pirsa_22010093, doi = {10.48660/22010093}, url = {https://pirsa.org/22010093}, author = {Ema, Yohei}, keywords = {Particle Physics}, language = {en}, title = {Higgs inflation, unitarity, and emergence of scalaron}, publisher = {Perimeter Institute}, year = {2022}, month = {jan}, note = {PIRSA:22010093 see, \url{https://pirsa.org}} }

Yohei Ema University of Minnesota

## Abstract

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.

Zoom Link: https://pitp.zoom.us/j/98015814051?pwd=YWdrWTJzbzJkdnFXRUxPWFJnNXVNQT09