On Classification of Models of Large Local-Type Non-Gaussianity

Understand

We classify models generating large local-type non-Gaussianity into some categories by using some "consistency relations" among the non-linearity parameters f_{NL}^{local}, \tau_{NL}^{local} and g_{NL}^{local}, which characterize the size of bispectrum for the former and trispectrum for the later two.

• Then we discuss how one can discriminate models of large local-type non-Gaussianity with such relations.
• We first classify the models by using the ratio of \tau_{NL}^{local}/(6f_{NL}^{local}/5)^2, which is unity for "single-source" models and deviates from unity for "multi-source" ones.
• We can make a further classification of models in each category by utilizing the relation between f_{NL}^{local} and g_{NL}^{local}.