The decay rate of metastable cosmic strings beyond the thin-string approximation
Abstract
In the context of grand unified theories, any cosmic strings present in the post-inflationary universe are likely to be metastable, with a decay rate set by the spontaneous creation of monopole pairs on the string. Determining this decay rate is crucial in understanding the phenomenology of the cosmic string network, including a potentially observable gravitational wave background. The bounce action governing this rate has so far only been determined using the thin string approximation or specific ansätze for the field profiles in the monopole formation process. Here we solve this problem using classical lattice simulations, relying only on the inherent symmetries of the problem. Our results indicate a suppression of the bounce action and hence a faster string decay compared to previous estimates.
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BibTeX
@misc{domcke2026decay,
title = {{The decay rate of metastable cosmic strings beyond the thin-string approximation}},
author = {Valerie Domcke and Yu Hamada},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2606.03008},
eprint = {2606.03008},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2606.03008},
}
RIS
TY - UNPB
TI - The decay rate of metastable cosmic strings beyond the thin-string approximation
AU - Valerie Domcke
AU - Yu Hamada
PY - 2026
DA - 2026/10/07
PB - arXiv
DO - 10.48550/arxiv.2606.03008
UR - https://arxiv.org/abs/2606.03008
AB - In the context of grand unified theories, any cosmic strings present in the post-inflationary universe are likely to be metastable, with a decay rate set by the spontaneous creation of monopole pairs on the string. Determining this decay rate is crucial in understanding the phenomenology of the cosmic string network, including a potentially observable gravitational wave background. The bounce action governing this rate has so far only been determined using the thin string approximation or specific ansätze for the field profiles in the monopole formation process. Here we solve this problem using classical lattice simulations, relying only on the inherent symmetries of the problem. Our results indicate a suppression of the bounce action and hence a faster string decay compared to previous estimates.
ER -