The low energy effective Lagrangian for photon interactions in any dimension

Abstract

The subject of low energy photon-photon scattering is considered in arbitrary dimensional space-time and the interaction is widened to include scattering events involving an arbitrary number of photons. The effective interaction Lagrangian for these processes in QED has been determined in a manifestly invariant form. This generalisation resolves the structure of the weak-field Euler-Heisenberg Lagrangian and indicates that the component invariant functions have coefficients related, not only to the space-time dimension, but also to the coefficients of the Bernoulli polynomial.

In the revised version, the results have been expressed in terms of Bernoulli polynomials instead of generalized zeta functions; they agree for spinor QED with those of Schubert and Schmidt (obtained differently by path integral methods).