Renormalization of O(N) model in 1/N expansion in auxiliary field formalism

Understand

We study the renormalization of the O(N) model using the auxiliary field formalism (Hubbard-Stratonovich transformation) in the 1/N expansion at finite temperature.

• We provide the general strategy of renormalization for arbitrary order, and make calculation up to next-to-leading order.
• We show that renormalization is possible for any values of the condensates, prove the temperature independence of the counterterms and determine the cutoff dependence of the first nontrivial counterterm parts.