Speaker
Description
The inflationary period in the early universe provides a widely accepted mechanism for generating primordial perturbations. While some single-field models successfully reproduce current observations, multifield models can lead to distinct observational signatures on scales much smaller than those probed by the cosmic microwave background. Multifield models of inflation introduce richer dynamics, including nonlinear evolution where standard perturbative methods break down. In this work, we extend existing numerical techniques to a general multifield setup. We explore the waterfall regime near the end of hybrid inflation, where tachyonic instabilities lead to fast, nonlinear growth of field fluctuations. Using lattice simulations, we follow the evolution of the coupled fields through this regime and compute the resulting curvature perturbations. These results demonstrate the importance of accurately describing multifield dynamics in nonlinear regimes. In particular, they highlight how nonlinear effects during the final stages of inflation can affect curvature perturbations and potentially leave observational signatures.
| Other topic / keywords: | Multifield inflation, lattice simulations |
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