Stochastic Inflation and Primordial Black Holes

by Vincent Vennin

Wednesday 22 Nov 2017, 13:00 → 14:00 Europe/Brussels

E/3rd floor-E.349 - Seminar room (E.349) (Marc de Hemptinne (chemin du Cyclotron, 2, Louvain-la-Neuve))

In the inflationary paradigm, the transition from quantum fluctuations to classical but stochastic density perturbations plays an important role. In particular, it implies that the super-Hubble degrees of freedom can be described with a classical stochastic theory, the “stochastic inflation” formalism. In this framework, the short-wavelength quantum fluctuations act as a classical noise on the dynamics of the super-Hubble scales.

I will explain which signatures are left by this quantum backreaction on the correlation functions of primordial cosmological perturbations. I will discuss the conditions under which these can be large even at sub-Planckian energy, and I will explain which prospects it opens for probing quantum gravity effects on inflationary dynamics. As an application, I will show how the formation of primordial black holes from inflation is dominated by these stochastic effects.