Primordial gravitational waves as a promising test for inflationary models.
Guzzetti M.C., Bartolo N., Liguori M., Matarrese S.
The cosmological inflationary model predicts the production of a stochastic background of gravitational waves (tensor modes). More precisely, several mechanisms of gravitational wave production can take place during inflation and a blue tensor power-spectrum can be generated too. Therefore, besides being a window on the origin of the Universe, primordial gravitational waves represent a powerful information messenger able to discriminate among inflationary models. In this direction, the many planned experiments for their direct/indirect detection assume a crucial role, for example in testing the validity/violation of the standard consistency relation between the tensor-to-scalar ratio and the tensor spectral index.