Leon Rosenfeld and the challenge of the vanishing momentum in quantum electrodynamics

TL;DR

This paper discusses Leon Rosenfeld's pioneering 1930 Hamiltonian approach to gauge theories, highlighting its historical significance and underappreciation due to the era's skepticism towards second quantization.

Contribution

It reveals Rosenfeld's early and complete formalism for gauge theories predating Dirac and Bergmann, emphasizing its overlooked importance in quantum electrodynamics history.

Findings

Rosenfeld's formalism predates Dirac and Bergmann.

His gauge fixing group-theoretical justification was overlooked.

Historical context affected recognition of Rosenfeld's work.

Abstract

Leon Rosenfeld published in 1930 the first systematic Hamiltonian approach to Lagrangian models that possess a local gauge symmetry. The application of this formalism to theories with local internal symmetries, such as electromagnetism in interaction with charged matter fields, is valid and complete, and predates by two decades the work by Dirac and Bergmann. Although he provided a group-theoretical justification for gauge fixing procedures that had just been implemented in the first expositions of quantum electrodynamics by Heisenberg and Pauli, and also by Fermi, his contribution went largely unnoticed. This lack of impact seems to be related to a generalized disenchantment with second quantization in the 1930's and 1940's.