A. Zee, Quantum Field Theory in a Nutshell · Problem VIII.4.6
Field Theory Redux
Physics — QFT
Problem
For any polynomial W(Φ) show that [W(Φ)]F=F[dW(ϕ)/dϕ]+ terms not involving F. Show that for the theory (11) the potential energy is given by V(ϕ†,ϕ)=∣∂W(ϕ)/∂ϕ∣2.