Enhancing Gravitational Waves from Global Strings via a First-Order Phase Transition
Abstract
We perform the first (3+1)-dimensional lattice simulations of a cosmological first-order phase transition (PT) in which true-vacuum bubbles with random phases nucleate, expand, and collide, producing a network of global strings. We find that the string network enters the scaling regime, and the coefficient of the logarithmic growth is smaller than the value obtained for a second-order PT. From the axion spectrum, we derive the dark-matter relic abundance and the dark-radiation bound from big bang nucleosynthesis on the axion decay constant fa and mass ma. The ratio of the gravitational wave emission rate to the axion emission rate is found to be about two orders of magnitude larger than in the second-order case, and the resulting gravitational wave spectrum can be probed by pulsar timing arrays as well as by space- and ground-based interferometers.
Related
- Gravitational Waves and Nambu-Goldstone Bosons from Infrared-Finite Cosmic Strings
- Interpretation of Nanohertz Gravitational Waves via Cosmic Strings in Post-BBN Matter and Kination Domination
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- High Energy Neutrinos, Gravitational Waves, and Dark Matter from a Cosmological First Order Phase Transition
- Impact of cosmic evolution on the gravitational wave spectrum from cosmic strings
BibTeX
@misc{jia2026enhancing,
title = {{Enhancing Gravitational Waves from Global Strings via a First-Order Phase Transition}},
author = {Yongtao Jia and Ligong Bian and Huai-Ke Guo},
howpublished = {arXiv},
year = {2026},
month = nov,
doi = {10.48550/arxiv.2611.07416},
eprint = {2611.07416},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2611.07416},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Enhancing Gravitational Waves from Global Strings via a First-Order Phase Transition
AU - Yongtao Jia
AU - Ligong Bian
AU - Huai-Ke Guo
PY - 2026
DA - 2026/11/05
PB - arXiv
DO - 10.48550/arxiv.2611.07416
UR - https://arxiv.org/abs/2611.07416
AB - We perform the first (3+1)-dimensional lattice simulations of a cosmological first-order phase transition (PT) in which true-vacuum bubbles with random phases nucleate, expand, and collide, producing a network of global strings. We find that the string network enters the scaling regime, and the coefficient of the logarithmic growth is smaller than the value obtained for a second-order PT. From the axion spectrum, we derive the dark-matter relic abundance and the dark-radiation bound from big bang nucleosynthesis on the axion decay constant f_a and mass m_a. The ratio of the gravitational wave emission rate to the axion emission rate is found to be about two orders of magnitude larger than in the second-order case, and the resulting gravitational wave spectrum can be probed by pulsar timing arrays as well as by space- and ground-based interferometers.
ER -