 Shift-symmetry soft theorem for a scalar bispectrum

ID: shift-symmetry-soft-theorem-for-a-scalar-bispectrum

If a scalar vacuum is invariant under an exact scalar-field shift symmetry, the Ward identity makes the leading soft bispectrum vanish:

lim_{q \to 0} \frac{B _{ϕ} ( q , k , ∣ k + q ∣ )}{P _{ϕ} ( q )} = 0.

 New to topics? Read the docs here!