Signatures of Primordial Gravitational Waves on the Large-Scale Structure of the Universe.

We study the generation and evolution of second-order energy-density perturbations arising from primordial gravitational waves. Such "tensor-induced scalar modes" approximately evolve as standard linear matter perturbations and may leave observable signatures in the large-scale structure of the Universe. We study the imprint on the matter power spectrum of some primordial models which predict a large gravitational-wave signal at high frequencies.