Contatto di riferimento: Barbara Simoni
Partecipanti: Franciolini Gabriele: University of Geneva
Abstract: Primordial black holes may owe their origin to the small-scale enhancement of the comoving curvature perturbation generated during inflation. Their abundance today is closely related to the mass fraction at formation. In the context of single-field models of inflation, the mechanism requires leaving the slow-roll phase to enter a non-attractor phase during which quantum diffusion has a significant impact on the primordial black hole mass fraction making the classical standard prediction not trustable. Furthermore, contrarily to what is often assumed, the PBH mass fraction at formation is markedly sensitive to possible non-Gaussianities in such large, but rare fluctuations. We present a path-integral formulation which provides the exact mass fraction of primordial black holes at formation in the presence of non-Gaussianity and we will show that restricting to a Gaussian statistics may lead to severe inaccuracies in the estimate of the mass fraction as well as on the clustering properties of the primordial black holes.