Primordial non-Gaussianity in multi-scalar slow-roll inflation

We analyse the non-Gaussianity for primordial curvature perturbations generated in a multi- scalar slow- roll inflation model including the model with non- separable potential by making use of delta N formalism. Many authors have investigated the possibility of large non-Gaussianity for the models with separable potential, and they have found that the non-linear parameter, fNL, is suppressed by the slow-roll parameters. We show that for the non-separable models fNL is given by the product of a factor which is suppressed by the slow-roll parameters and a possible enhancement factor which is given by exponentials of quantities of O(1).