Detecting primordial features with LISA

Abstract Oscillations in the frequency profile of stochastic gravitational wave background are a characteristic prediction small-scale features during inflation. In this paper we present first investigation detection prospects such oscillations with upcoming space-based observatory LISA. As proof principle, show for selection feature signals that can be reconstructed LISA, employing method based on principal component analysis. We then perform Fisher forecast parameters describing oscillatory signal. For sharp distinguish between contributions to induced inflation and post-inflationary period, which peak at different frequencies. find latter case amplitude oscillation is expected measurable < 10% accuracy if corresponding satisfies h 2 Ω GW ≳ 10 -12 -10 -11 , while inflationary-era waves requires higher as only appear UV tail spectrum. resonant LISA maximised falls into range ω log = 4 10. Our results confirm worthwhile target future efforts offer key experimentally testing small scales.