The trispectrum in ghost inflation

Abstract

We calculate the trispectrum in ghost inflation where both the contact diagram and scale-exchange diagram are taken into account. The shape of trispectrum is discussed carefully and we find that the local form is absent in ghost inflation. In general, for the non-local shape trispectrum there are not analogous parameters to ${\tau }_{NL}^{loc.}$ and $g_{NL}^{loc.}$ which can completely characterize the size of local form trispectrum.

Comments: 19 pages, 8 figures; clarifications and corrections added, version accepted for publication in JCAP