An Alternative to Perturbative Renormalization in 3+1 Dimensional Field Theories

Perturbative renormalization provides the bedrock of understanding quantumfield theories. In this work, I point out an alternative way of renormalizingquantum field theories, which is naturally encountered and well known for thecase of large N scalar field theories. In terms of bare parameters, thisnon-perturbative alternative renormalization differs qualitatively from itsperturbative cousin: in the continuum limit, the bare coupling constant goes tozero instead of infinity, and there is no wave-function counterterm. Despitethese differences, the resulting n-point functions of the theory are finite. Iprovide explicit results for alternative renormalization for the O(N) model andQCD with N_f=12 flavors in 3+1 dimensions.