QED fermions in a noisy magnetic field background

We consider the effects of a noisy magnetic field background over the fermion propagator in QED as an approximation to the spatial inhomogeneities that would naturally arise in certain physical scenarios, such as heavy-ion collisions or the quark-gluon plasma in the early stages of the evolution of the Universe. We considered a classical, finite, and uniform average magnetic field background hBox thorn i = B, subject to white-noise spatial fluctuations with autocorrelation of magnitude Delta B. By means of the Schwinger representation of the propagator in the average magnetic field as a reference system, we used the replica formalism to study the effects of the magnetic noise in the form of renormalized quasiparticle parameters, leading to an effective charge and an effective refraction index that depend not only on the energy scale, as usual, but also on the magnitude of the noise Delta B and the average field B.

Automated summary

We study the effects of a noisy magnetic field background on the fermion propagator in QED, as an approximation to spatial inhomogeneities in physical scenarios like heavy-ion collisions or the early stages of the Universe. A classical, finite, and uniform average magnetic field hBox thorn i = B is considered, with white-noise spatial fluctuations of magnitude Delta B. Using the Schwinger representation and replica formalism, we find that the magnetic noise leads to renormalized quasiparticle parameters with energy scale dependence as well as dependence on the magnitude of the noise Delta B and the average field B.