BLACK-HOLES AND GRAVITATIONAL-WAVES IN STRING COSMOLOGY - ART. NO. 063508

Pre-big-bang models of inflation based on string cosmology produce a s tochastic gravitational wave background whose spectrum grows with decr easing wavelength, and which may be detectable using interferometers s uch as LIGO. We point out that the gravitational wave spectrum is clos ely tied to the density perturbation spectrum, and that the condition for producing observable gravitational waves is very similar to that f or producing an observable density of primordial black holes. Detectio n of both would provide strong support to the string cosmology scenari o. [S0556-2821(98)00920-5].