Novel duality-invariant theories of electrodynamics

TL;DR

This paper introduces new duality-invariant electrodynamics theories, including an algorithm to generate families of such theories from a seed theory and two novel classes extending existing models.

Contribution

It presents an algorithm for constructing duality-invariant theories and identifies two new families of theories with unique properties.

Findings

Developed an algorithm to generate duality-invariant theories from a seed theory.

Discovered two new families of duality-invariant theories, including generalizations of Bialynicki-Birula electrodynamics.

Established conditions under which the constructed theories remain causal.

Abstract

We identify new families of duality-invariant theories of electrodynamics. We achieve this in two different ways. On the one hand, we present an algorithm to construct a one-parameter family of exactly duality-invariant theories from a single seed duality-invariant theory. If the seed theory is causal, the theories constructed from this method will also be causal when the parameter is non-negative. On the other hand, we find two additional novel families of duality-invariant theories which include a nonzero term independent of the electromagnetic field. The first of them generalizes Bialynicki-Birula electrodynamics, while the second family of theories features a well-defined Maxwell limit as the term independent of the gauge field strength is sent to zero.