Non-Gaussianity from Particle Production during Inflation

Figure 14

The shape function 𝑆(𝑘,𝑘𝑥₂,𝑘𝑥₃), defined by (132), as a function of the dimensionless quantities 𝑥₂,𝑥₃ which parametrize the shape of the triangle. (a) corresponds to 𝑘=𝑒⁻¹𝑘_bump, (b) is 𝑘=𝑘_bump, (c) is 𝑘=𝑒⁺¹𝑘_bump, and (d) is 𝑘=𝑒⁺²𝑘_bump. In the IR (𝑘≤𝑘_bump) the shape of the bispectrum is similar to the equilateral shape; however, there is also some support on flattened triangles near 𝑘∼𝑒⁺¹𝑘_bump. At larger values of 𝑘 the shape is unlike any other template proposed in the literature.

(a)

(b)

(c)

(d)