Geodesic deviation in field space: flattened non-gaussianities and PBH
2020-02-27
14:00
UB
Aula 507 (Pere Pascual, ICC building, UAB Campus)
Several recent proposals to embed inflation into high-energy physics rely on inflationary dynamics characterized by a strongly non-geodesic motion. This in turn relaxes the conditions of slow-roll to allow for potentials that are steep in Planck units, a welcome feature in view of the eta problem and the recently much discussed swampland conjectures.
In this talk I will present a general framework to study non-Gaussianities in the presence of non-geodesic trajectories in field space. I will then highlight how non-geodesic motion in field space naturally leads to “hyper-non-Gaussianities”, i.e. the bispectrum and all higher-order correlation functions are hierarchically enhanced for particular flattened configurations.
Towards the end I will discuss how a similar mechanism can induce a significant enhancement of the power spectrum on small scales providing an interesting new possibility to generate primordial black holes.