Landau Singularity and the Instability of Vacuum State in QED

Abstract

In this paper, we argue that the Landau singularity of the coupling constant in QED reflects the instability of vacuum state, in other words the perturbative ground state in QED.We do not have a rigorous mathematical proof. We rather provide strong arguments derived from the theory of stability of matter developed by Lieb et al on the hand and the theory of weakly interacting fermion systems developed by Feldman et al on the other hand.