Monodromy inflation at strong coupling: $4\pi$ in the sky

We present a simple effective field theory formulation of a general family of single-field flux monodromy models for which strong coupling effects at large field values can flatten the potential and activate higher-derivative operators. Both of these effects can suppress the tensor amplitude. These models are radiatively and nonperturbatively stable and can sustain ≳60 e folds of inflation. The dynamics combines features of both large-field chaotic inflation and k inflation. Reducing the tensor-scalar ratio below the observational bound r≲0.1 while keeping the scalar spectral index ns within experimental bounds either yields equilateral non-Gaussianity fNLeq≃O(1), close to the current observational bounds, or gives very small r.