DOMAIN BOUNDARIES, GOLDSTONE BOSONS AND GRAVITATIONAL-WAVES

The dynamical behaviour of domain boundaries between different realiza tions of the vacuum of scalar fields with spontaneously broken phases is investigated. They correspond to zero-modes of the Goldstone fields , moving with the speed of light, and rum out to be accompanied by str ongly oscillating gravitational fields. In certain space-time topologi es this leads to a quantization condition for the symmetry breaking sc ale in terms of the Planck mass.