A. Zee, Quantum Field Theory in a Nutshell · Problem VII.4.7
Field Theory Redux
Physics — QFT
Problem
For V(ϕ)=21m2ϕ2+gϕ4, determine ρ(E). For m2 sufficiently negative (the double well potential again) we expect the density of eigenvalues to split into two pieces. This is evident from the Dyson gas picture. Find the critical value mc2. For m2<mc2 the assumption of G(z) having only one cut used in the text fails. Show how to calculate ρ(E) in this regime.