Gravitational waves from domain walls and their implications

Understand

We evaluate the impact of domain-wall annihilation on the currently ongoing and planned gravitational wave experiments, including a case in which domain walls experience a frictional force due to interactions with the ambient plasma.

• We show the sensitivity reach in terms of physical parameters, namely, the wall tension and the annihilation temperature.
• We find that a Higgs portal scalar, which stabilizes the Higgs potential at high energy scales, can form domain walls whose annihilation produces a large amount of gravitational waves within the reach of the advanced LIGO experiment (O5).
• Domain wall annihilation can also generate baryon asymmetry if the scalar is coupled to either SU(2)$_L$ gauge fields or the $(B-L)$ current.