Multi-field inflation with large scalar fluctuations: non-Gaussianity and perturbativity

Understand

Recently multi-field inflation models that can produce large scalar fluctuations on small scales have drawn a lot of attention, primarily because they could lead to primordial black hole production and generation of large second-order gravitational waves.

• In this work, we focus on models where the scalar fields responsible for inflation live on a hyperbolic field space.
• In this case, geometrical destabilisation and non-geodesic motion are responsible for the peak in the scalar power spectrum.
• We present new results for scalar non-Gaussianity and discuss its dependence on the model's parameters.