Work

String-induced vacuum decay and its gravitational wave signatures

Year: 2026

Type: article

Abstract: False vacuum decay typically proceeds via the nucleation of spherical bubbles of true vacuum, described by O ( 4 ) symmetric field configurations in Euclidean time. In this work, we investigate how the presence of cosmic strings can catalyze the decay process. To this end, we consider a complex scalar field charged under a global or local U ( 1 ) symmetry. Assuming a nontrivial vacuum manifold, realizable for example in a simple sextic potential, we derive relativistic bounce solutions with O ( 2 ) × O ( 2 ) symmetry, corresponding to elongated bubbles seeded by a cosmic string of the same scalar field. Building up on earlier results in the literature, we identify the region of parameter space where vacuum decay predominantly proceeds via this alternative channel, thereby providing an explicit mechanism for the quantum decay of cosmic strings. Finally, we present an initial discussion of the gravitational wave signal associated with this type of vacuum decay and its possible connection to the recently observed stochastic signal in pulsar timing arrays.

Source: Physical review. D/Physical review. D.

DOI: 10.1103/72d2-kc3n

Authors: Aleksandr Chatrchyan, Florian Niedermann, Phoebe Richman-Taylor

Institutions: Nordic Institute for Theoretical Physics, Stockholm University, KTH Royal Institute of Technology, University of Iceland

Language: English

Topic: Cosmology and Gravitation Theories

Subfield: Astronomy and Astrophysics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: hybrid

Funders: Vetenskapsrådet, Háskóli Íslands

Awards: Exploring the dark sector with new microphysics in the early universe, Detecting Axion Dark Matter In The Sky And In The Lab, Astronomical Signals from Axions and Axion-Like Particles