%0 Journal Article %T Equilateral non-Gaussianity from heavy fields %A Jinn-Ouk Gong %A Shi Pi %A Misao Sasaki %J Physics %D 2013 %I arXiv %R 10.1088/1475-7516/2013/11/043 %X The effect of self-interactions of heavy scalar fields during inflation on the primordial non-Gaussianity is studied. We take a specific constant-turn quasi-single field inflation as an example. We derive an effective theory with emphasis on non-linear self-interactions of heavy fields and calculate the corresponding non-Gaussianity, which is of equilateral type and can be as relevant as those computed previously in the literature. We also derive the non-Gaussianity by directly using the in-in formalism, and verify the equivalence of these two approaches. %U http://arxiv.org/abs/1306.3691v1