Cosmological consequences of string-forming open inflation models

We present a study of open inflation cosmological scenarios in which cosmic strings form between the two inflationary epochs. It is shown that ill these models, strings are stretched outside the horizon due to the inflationary expansion, but must necessarily re-enter the horizon before the epoch of equal matter and radiation densities; We determine the linear power spectrum of cold dark matter perturbations in these hybrid models, finding good agreement with observations for values of Gamma = Omega(0)h similar to 0.3 and comparable contributions from the active and passive sources to the cosmic microwave background. Finally, we briefly discuss other cosmological consequences of these models. [S0556-2821(99)03712-1].