From NANOGrav to LIGO with metastable cosmic strings

• DOI: 10.1016/j.physletb.2020.135914
• Publication Date: 2020-11-05T16:46:15Z
• Authors: Wilfried Buchmuller; Valerie Domcke; Kai Schmitz
• Keywords: Cosmology and Nongalactic Astrophysics (astro-ph.CO); gravitational radiation: stochastic; QC1-999; interferometer; FOS: Physical sciences; 530; 01 natural sciences; dark matter; magnetic monopole: mass; High Energy Physics - Phenomenology (hep-ph); evolution; 0103 physical sciences; inflation; LIGO; info:eu-repo/classification/ddc/530; cosmic string; leptogenesis; string tension; Physics; gravitational radiation: background; spontaneous symmetry breaking; High Energy Physics - Phenomenology; * Automatic Keywords *; grand unified theory; B-L number; Astrophysics - Cosmology and Nongalactic Astrophysics

We interpret the recent NANOGrav results in terms of a stochastic gravitational wave background from metastable cosmic strings. The observed amplitude of a stochastic signal can be translated into a range for the cosmic string tension and the mass of magnetic monopoles arising in theories of grand unification. In a sizable part of the parameter space, this interpretation predicts a large stochastic gravitational wave signal in the frequency band of ground-based interferometers, which can be probed in the very near future. We confront these results with predictions from successful inflation, leptogenesis and dark matter from the spontaneous breaking of a gauged B-L symmetry.