Pseudo-Nambu-Goldstone Boson Production from Inflaton Coupling during Reheating
Abstract
The existence of pseudo-Nambu-Goldstone boson (pNGB) fields is a common feature in many models beyond the Standard Model, characterized by their exclusive derivative couplings. This paper investigates a scenario where a pNGB is coupled to the inflaton field during the reheating phase of the early universe. We calculate the perturbative decay rate of a coherently oscillating inflaton into pNGBs on a general basis, considering both constant and field-dependent couplings with monomial potentials at the minimum. As a concrete application, we explore the production of axions when the radial mode of the Peccei-Quinn (PQ) scalar serves as the inflaton, particularly in the presence of a large gravitational non-minimal coupling. Our findings suggest that the presence of pNGBs during reheating can lead to significant non-thermal relics, offering new constraints on inflationary reheating models and providing potential observational signatures in the form of dark radiation.
Keywords
Cite
@article{arxiv.2406.09045,
title = {Pseudo-Nambu-Goldstone Boson Production from Inflaton Coupling during Reheating},
author = {Kunio Kaneta and Sung Mook Lee and Kin-ya Oda and Tomo Takahashi},
journal= {arXiv preprint arXiv:2406.09045},
year = {2024}
}
Comments
19 pages, 3 figures