On the energy of physical states in QED in the convariant gauge

TL;DR

This paper demonstrates that in quantum electrodynamics (QED) using a covariant gauge, the energy of physical states is unbounded from below, challenging the common assumption of a lower energy bound in quantum field theory.

Contribution

It reveals that the energy spectrum of physical states in QED in a covariant gauge is unbounded from below, providing new insights into the theory's foundational assumptions.

Findings

Energy of physical states in QED is unbounded from below.

Challenges the assumption of a lower energy bound in quantum field theory.

Highlights issues with covariant gauges in QED.

Abstract

In quantum field theory it is generally assumed that there is a lower bound to the energy of a quantum state. Here, it will be shown that there is no lower bound to the energy of physical states in QED in a manifestly covariant gauge.