  In this paper we consider how non-Gaussianity of the primordial density
perturbation and the amplitude of gravitational waves from inflation can be
used to determine parameters of the curvaton scenario for the origin of
structure. We show that in the simplest quadratic model, where the curvaton
evolves as a free scalar field, measurement of the bispectrum relative to the
power spectrum, fNL, and the tensor-to-scalar ratio can determine both the
expectation value of the curvaton field during inflation and its dimensionless
decay rate relative to the curvaton mass. We show how these predictions are
altered by the introduction of self-interactions, in models where higher-order
corrections are determined by a characteristic mass scale and discuss how
additional information about primordial non-Gaussianity and scale dependence
may constrain curvaton interactions.
