Tilt and Running of Cosmological Observables in Generalized Single-Field
  Inflation
  Employing an effective field theory approach to inflationary perturbations,
we analyze in detail the effect of curvature-generated Lagrangian operators on
various observables, focusing on their running with scales. At quadratic order,
we solve the equation of motion at next-to-leading leading order in a
generalized slow-roll approximation for a very general theory of single-field
inflation. We derive the resulting power spectrum, its tilt and running. We
then focus on the contribution to the primordial non-Gaussianity amplitude
f_{NL} sourced by a specific interaction term. We show that the running of
f_{NL} can be substantially larger than what dictated by the slow-roll
parameters.
