Angelika Fertig

Bouncing cosmology 2: the bouncing phase

Bouncing cosmology 1: intro,overview, the ekpyrotic phase.

In this talk, I will show how entropy perturbations created during a contracting phase and converted into adiabatic/curvature perturbations after a bounce form the dominant contribution to the observed temperature fluctuations in the CMB.

In this talk I derive the evolution equations for two scalar fields with non-canonical field space metric up to third order in perturbation theory, employing the covariant formalism. These equations can be used to calculate the local bi- and trispectra of the non-minimal ekpyrotic model. Remarkably, the nearly scale-invariant entropy perturbations have vanishing bi- and trispectra during the ekpyrotic phase.