Thomas Iser Baryon and Lepton Number Violation from Gravitational Waves Bartosz Fornal, Barmak Shams Es Haghi Hide abstract | Show figures | Show BibTeX | Show discussion | View PDF | 2008.05111v1 We describe a unique gravitational wave signature for a class of models with a vast hierarchy between the symmetry breaking scales. The unusual shape of the signal is a result of the overlapping contributions to the stochastic gravitational wave background from cosmic strings produced at a high scale and a cosmological phase transition at a low scale. We apply this idea to a simple model with gauged baryon and lepton number, in which the high-scale breaking of lepton number is motivated by the seesaw mechanism for the neutrinos, whereas the low scale of baryon number breaking is required by the observed dark matter relic density. The novel signature can be searched for in upcoming gravitational wave experiments. Authors' comments: 7 pages, 4 figures