Gravitational radiation from primordial solitons and soliton-star binaries

The possibility that both the formation of nontopological solitons in a primordial second-order phase transition and binary systems of soliton stars could generate a stochastic gravitational-wave background is examined. The present contribution in gravitational radiation to the energy density of the Universe from these processes is estimated for a number of different models. The detectability of such contributions from the timing measurements of the milisecond pulsar and spaceborne laser interferometry is briefly discussed and compared to other cosmological and local sources of background gravitational waves.