Speaker
Description
I will show that a new gravitational wave signature is expected in extensions of the Standard Model with extra gauge symmetries broken at vastly different energy scales. The spectrum contains a characteristic double-peak structure consisting of a sharp peak from domain walls and a smooth bump from a first order phase transition in the early Universe. I will provide an example of such a model, with baryon number and color unified into an SU(4) gauge group and lepton number promoted to an SU(2) gauge symmetry. The model contains two types of dark matter particles, accommodates leptogenesis, and provides nonzero neutrino masses. I will discuss how future gravitational wave experiments, such as LISA, Big Bang Observer, DECIGO, Einstein Telescope, and Cosmic Explorer, can be used to look for this novel signature.
