Trispectrum from ghost inflation

Ghost inflation predicts almost scale-invariant primordial cosmological perturbations with relatively large non-Gaussianity. The bispectrum is known to have a large contribution at the wavenumbers forming an equilateral triangle and the corresponding nonlinear parameter f(NL)(equil) is typically of order O(10(2)). In this paper we calculate trispectrum from ghost inflation and show that the corresponding nonlinear parameter tau(NL) is typically of order O(10(4)). We investigate the shape dependence of the trispectrum and see that it has some features different from DBI inflation. Therefore, our result may be useful as a template to distinguish ghost inflation from other models of inflation by future experiments.