Eq. (4.9): $-f_{NL} = \frac53\frac{\mathcal A}{4\sum_ik_i^3} = -\frac{5}{12}(n_s+f(k)n_t)$

Initializing...

Eq. (4.9): $-f_{NL} = \frac53\frac{\mathcal A}{4\sum_ik_i^3} = -\frac{5}{12}(n_s+f(k)n_t)$ · Prove2Me