Lattice simulations find the bounce action for metastable cosmic string decay suppressed compared to thin-string estimates, implying faster decay.
Metastable strings at PTAs: classical stability analysis
2 Pith papers cite this work. Polarity classification is still indexing.
abstract
Metastable strings can arise from a two-step symmetry breaking chain of the type $SU(2) \to U(1) \to 1$.They can decay through quantum tunneling by nucleating a monopole-antimonopole pair, and are prominent candidates for explaining the gravitational wave background detected at Pulsar Timing Arrays (PTAs).We investigate the classical stability of the strings arising in this commonly-considered setup, which serves as a fundamental input for discussing their possible decay channels. We identify the regions of parameter space in which the strings are either classically stable or unstable. Our results show that classical instabilities can impact the parameter space relevant for PTAs. We also discuss the possible fate of the string network in the regions of classical instability.
fields
hep-ph 2years
2026 2verdicts
UNVERDICTED 2representative citing papers
Thermal effects shift the PTA-compatible parameter region in a minimal dark-sector model to lower dark fine-structure constant and higher monopole-to-string-tension ratio by making thermally induced nucleation the dominant decay channel for metastable Z-strings.
citing papers explorer
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The decay rate of metastable cosmic strings beyond the thin-string approximation
Lattice simulations find the bounce action for metastable cosmic string decay suppressed compared to thin-string estimates, implying faster decay.
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Thermal Metastable Strings in One-Scale Models and Gravitational Waves
Thermal effects shift the PTA-compatible parameter region in a minimal dark-sector model to lower dark fine-structure constant and higher monopole-to-string-tension ratio by making thermally induced nucleation the dominant decay channel for metastable Z-strings.