From NANOGrav to LIGO with metastable cosmic strings

Understand

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.