Casimir Effects in Renormalizable Quantum Field Theories

TL;DR

This paper reviews a method for calculating one-loop quantum corrections in renormalizable quantum field theories, transforming mode sums into phase shift integrals for better divergence control and numerical computation.

Contribution

It introduces a novel approach that relates phase shifts to Feynman diagrams for effective divergence subtraction in Casimir effect calculations.

Findings

Method effectively isolates divergences in Casimir calculations.

Approach applicable to solitons, membranes, and external field problems.

Numerical convergence improved through phase shift representation.

Abstract

We review the framework we and our collaborators have developed for the study of one-loop quantum corrections to extended field configurations in renormalizable quantum field theories. We work in the continuum, transforming the standard Casimir sum over modes into a sum over bound states and an integral over scattering states weighted by the density of states. We express the density of states in terms of phase shifts, allowing us to extract divergences by identifying Born approximations to the phase shifts with low order Feynman diagrams. Once isolated in Feynman diagrams, the divergences are canceled against standard counterterms. Thus regulated, the Casimir sum is highly convergent and amenable to numerical computation. Our methods have numerous applications to the theory of solitons, membranes, and quantum field theories in strong external fields or subject to boundary conditions.