Introduction

Abstract

In quantum field theory, we often encounter field configurations with a strongly localized energy or charge density. In many cases, these configurations also solve the classical field equations and in many respects behave as classical particles; such configurations are known as solitons [1, 2]. While it is generally straightforward to compute the classical energy of such a configuration, the quantum correction to the classical energy is often essential to complete the physical picture. For reasons that will soon become obvious, this correction is commonly called the vacuum polarization energy. Vacuum polarization energies have been investigated for soliton configurations ranging from simple models in 1 + 1 dimensions [2, 3] to chiral models for baryons1 [5, 6] and even to cosmic strings in the standard model [7, 8].