We study the evolution of tensor metric fluctuations in a class of non-singular models based on the string effective action, by including in the perturbation equation the higher-derivative and loop corrections needed to regularise the background solutions. We discuss the effects of such higher-order corrections on the final graviton spectrum, and we compare the results of analytical and numerical computations. © 2001 Elsevier Science B.V.
Cartier, C., Copeland, E. J., & Gasperini, M. (2001). Gravitational waves in non-singular string cosmologies. Nuclear Physics B, 607(1–2), 406–428. https://doi.org/10.1016/S0550-3213(01)00182-1