Light Scalars and the Cosmos: Nambu-Goldstone and Otherwise

TL;DR

This paper discusses the significance of light scalar particles, including Nambu-Goldstone bosons and pseudo moduli, in cosmology, highlighting their roles in dark matter and inflationary models.

Contribution

It explores the cosmological implications of light scalars, emphasizing their potential as dark matter candidates and drivers of various inflationary scenarios.

Findings

QCD axions could be dark matter candidates.

Light scalars can naturally facilitate large field inflation.

Pseudo moduli may mimic chaotic inflation under certain conditions.

Abstract

This talk focuses on the role of light scalars in cosmology, both Nambu Goldstone bosons and pseudo moduli. The former include QCD axions, which might constitute the dark matter, and more general axions, which, under certain conditions, might play the role of inflatons, implementing {\it natural inflation}. The latter are the actors in (generalized) hybrid inflation. They rather naturally yield large field inflation, even mimicking chaotic inflation for suitable ranges of parameters.