Pseudo-Nambu-Goldstone inflation with ZN symmetric waterfall fields
Abstract
We propose a hybrid inflation model where a pseudo-Nambu-Goldstone boson inflaton couples to N waterfall scalar fields respecting a ZN symmetry. We identify the phases for the inflation and the consequent waterfall transition, concretely, in Z2, Z3 and Z4 cases. From the Coleman-Weinberg potential for the inflaton, we show that the quadratically divergent corrections coming from the waterfall sector are cancelled due to the ZN symmetry, while the logarithmically divergent corrections are absent only for N>2, ensuring the radiative stability of the inflaton potential. We show the parameter space for a successful inflation with the loop-corrected inflaton potential in each model and compare the results between different discrete symmetries. We further analyze the vacuum structure of the models and the reheating process due to the ZN-invariant Higgs-portal couplings for the waterfall fields. We find that the maximum temperature can be smaller than the mass of the waterfall field condensate such that the ZN symmetry is not restored after reheating and there is no domain wall problem in the models. We also comment on the possibility of multi-component dark matter from the ZN partners of the waterfall field condensate.
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BibTeX
@misc{lee2026pseudonambugoldstone,
title = {{Pseudo-Nambu-Goldstone inflation with $Z_N$ symmetric waterfall fields}},
author = {Hyun Min Lee and Adriana G. Menkara},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.22464},
eprint = {2605.22464},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.22464},
note = {CC BY-NC-SA 4.0},
}
RIS
TY - UNPB
TI - Pseudo-Nambu-Goldstone inflation with Z_N symmetric waterfall fields
AU - Hyun Min Lee
AU - Adriana G. Menkara
PY - 2026
DA - 2026/09/25
PB - arXiv
DO - 10.48550/arxiv.2605.22464
UR - https://arxiv.org/abs/2605.22464
AB - We propose a hybrid inflation model where a pseudo-Nambu-Goldstone boson inflaton couples to N waterfall scalar fields respecting a Z_N symmetry. We identify the phases for the inflation and the consequent waterfall transition, concretely, in Z_2, Z_3 and Z_4 cases. From the Coleman-Weinberg potential for the inflaton, we show that the quadratically divergent corrections coming from the waterfall sector are cancelled due to the Z_N symmetry, while the logarithmically divergent corrections are absent only for N>2, ensuring the radiative stability of the inflaton potential. We show the parameter space for a successful inflation with the loop-corrected inflaton potential in each model and compare the results between different discrete symmetries. We further analyze the vacuum structure of the models and the reheating process due to the Z_N-invariant Higgs-portal couplings for the waterfall fields. We find that the maximum temperature can be smaller than the mass of the waterfall field condensate such that the Z_N symmetry is not restored after reheating and there is no domain wall problem in the models. We also comment on the possibility of multi-component dark matter from the Z_N partners of the waterfall field condensate.
ER -