Gravitational shine of dark domain walls

Cosmic domain walls are harmless, provided that their tension decreases with expansion of the Universe. This setup can be realized, if scale spontaneous symmetry breaking is induced dynamically through interaction hot primordial plasma. In case, wall attain large values in early Universe without any conflict observations. Owing to initial tension, these topological defects may serve as a powerful source gravitational waves. We make preliminary estimate wave spectrum and argue it distinct from produced by other sources, particular constant tension. The resulting signal range accessible Einstein Telescope, DECIGO, TianQin, LISA, IPTA, or SKA, field constituting very feebly coupled plasma has tiny self-interactions. particular, one consider this for role Dark Matter. discuss various Matter production mechanisms properties emitted waves associated them. find conventional freeze-out freeze-in lead perhaps unobservable frequency However, also possible at second order phase transition leading formation inverse transition, when get dissolved eventually. both cases, there essentially no lower bound on