Hard thermal loops in static background fields

Abstract

We discuss the high-temperature behavior of retarded thermal loops in static external fields. We employ an analytic continuation of the imaginary-time formalism and use a spectral representation of the thermal amplitudes. We show that, to all orders, the leading contributions of static hard thermal loops can be directly obtained by evaluating them at zero external energies and momenta. © 2013 Springer-Verlag Berlin Heidelberg and Società Italiana di Fisica.