Composite hybrid inflation: dilaton and waterfall pions

Abstract

We investigate the possibility that inflation originates from a composite field theory, in terms of an effective chiral Lagrangian involving a dilaton and pions. The walking dynamics of the theory constrain the potential in a specific way, where the anomalous dimensions of operators involving pions play a crucial role. For realistic values of the anomalous dimensions, we find a successful hybrid inflation occurring via the dilaton-inflaton, with the pions acting as waterfall fields. Compositeness consistency strongly constrain the model, predicting a dilaton scale fχ ∼ 𝒪 (1) in unit of the Planck scale, an inflation scale H inf ∼ 1010 GeV, and the pion scale around 1014 GeV. We further discuss possible phenomenological consequences of this theory.