Primordial non-Gaussianity in noncanonical warm inflation: Three-and four-point correlations

摘要

Non-Gaussianity generated in inflation can be contributed by two parts. The first part, denoted by f_(NL)~(δN), is the contribution from the four-point correlation of the inflaton field which can be calculated using δN formalism, and the second part, denoted by f_(NL)~(int), is the contribution from the three-point correlation function of the inflaton field. We consider the two contributions to the non-Gaussianity in noncanonical warm inflation throughout (noncanonical warm inflation is a new inflationary model which is proposed in X. M. Zhang and J. Y. Zhu, Phys. Rev. D 90, 123519 (2014)). We find the two contributions are complementary to each other. The four-point correlation contribution to the non-Gaussianity is overwhelmed by the three-point one in the strong noncanonical limit, while the conclusion is the opposite in the canonical case. We also discuss the influence of the field redefinition, thermal dissipative effect and noncanonical effect to the non-Gaussianity in noncanonical warm inflation.