Observable Gravitational Waves and Spectral Index Running in Small
  Single Field Inflationary Models
  I construct a class of single small field models of inflation that can
predict an observable gravitational wave signal in the cosmic microwave
background anisotropoies, contrary to popular wisdom. The spectral index, its
running, the tensor to scalar ratio and the number of e-folds can cover all the
parameter space currently allowed by cosmological observations. A unique
feature of models in this class is their ability to predict a negative spectral
index running in accordance with recent cosmic microwave background
observations. I comment on the new class of models from an effective field
theory perspective and show that if the dimensionless trilinear coupling is
small, as required for consistency, then the observed spectral index running
implies a high scale of inflation and hence an observable gravitational wave
signal.
