Comments on QED with background electric fields

Abstract

It is well known that there is a total cancellation of the \emph{factorizable} IR divergences in unitary interacting field theories, such as QED and quantum gravity. In this note we show that such a cancellation does not happen in QED with background electric fields which can produce pairs. There is no factorization of the IR divergences.Comment: 14 pages, 1 figur