Speaker
Description
Primordial gravitational waves (GWs) can source scalar density perturbations at second order, thereby leaving indirect but potentially observable signatures in the large-scale structure (LSS) of the Universe. In this talk, I will present a comprehensive study of these tensor-induced density perturbations, from their analytic evolution in the radiation- and matter-dominated eras to their non-Gaussian statistics and implications for biased tracers. I will discuss how GWs energy density fluctuations generate the matter density contrast, how the resulting bispectrum depends on the shape of the primordial GWs spectrum, and how this non-Gaussianity propagates into observables such as halo bias. These results show that LSS offers a complementary probe of primordial GWs, extending the search for early-Universe tensor modes beyond the traditional GWs detectors alone.