Abstract

Observational constraints and prospects for detection of features, i.e. oscillations in the primordial power spectrum, have so far concentrated on the CMB and Large Scale Structure surveys. After a broad introduction, I will show how different features in the primordial spectrum lead to characteristic oscillatory patterns in the cosmological stochastic gravitational wave background. Probing these features could, for instance, establish the existence of heavy particles beyond the reach of terrestrial experiments, and even test the inflationary paradigm or point to alternatives to it. Further, high energy embeddings of inflation often lead to departures from the single-field slow-roll paradigm, resulting in features in the primordial scalar power spectrum. This provides a clear target for gravitational wave observatories as well as a challenge for developing dedicated data analysis techniques to look for this unique insight into the physics of the early universe.