High Energy Physics Seminar

We consider a quasi-single field inflation model in which the inflaton interacts with another massive scalar field called the isocurvaton.  Due to the breaking of time translational invariance by the inflaton background, these interactions induce kinetic mixing between the inflaton and isocurvaton, which is parameterized by a constant $\mu$.  We derive analytic formulae for the curvature perturbation 2, 3, 4, 5, and 6 point functions explicitly in terms of the external momenta in the limit where $\mu$ and the mass of the isocurvaton $m$ are both much smaller than $H$.  In previous work, it has been noted that when $m$ and $\mu$ are small, the non-gaussianities predicted by quasi-single field inflation give rise to long-wavelength enhancements of the two point function of biased objects.  We compute these enhanced contributions to the two and three point functions of biased objects and determine the momenta at which they are larger than the guassian contribution.  We also identify the scaling of these enhanced contributions to the n-point function of biased objects.