Large non-gaussianity from multi-brid in ation

A model of multi-component hybrid ination, dubbed multi-brid ination, which may yield a large non-Gaussian paramter fNL, was proposed recently. In particular, for a two-brid ination model with an exponential potential and the condition that the end of ination is an ellipse in the field space, it was found that, while keeping the other observational quantities within the range consistent with observations, large non-Gaussianity is possible for certain inationary trajectories. In this talk, in order to see if this result is a general feature of multi-brid ination, we consider a model with a potential with an exponent quadratic in the scalar field components. We also consider a more general class of ellipses for the end of ination. Focusing on the case of two-brid ination, we find that large non-Gaussianity is also possible in the present model. Then by tuning the model parameters, we find that there exist models for which both the non-Gaussianity and the tensor-to-scalar ratio are large enough to be detected in the very near future.