Comment on covariant duality symmetric actions

TL;DR

The paper critiques a proposed duality symmetric action for Maxwell theory, revealing it introduces extra degrees of freedom and is not suitable for a single gauge field.

Contribution

It clarifies that the existing duality symmetric action includes additional propagating fields, challenging its validity as a true duality symmetric formulation.

Findings

The action contains extra vector degrees of freedom.

It cannot be considered a duality symmetric action for a single gauge field.

The critique clarifies the limitations of the proposed formulation.

Abstract

We demonstrate that an action proposed by A. Khoudeir and N. R. Pantoja in {\sl Phys. Rev.} {\bf D53}, 5974 (1996) for endowing Maxwell theory with manifest electric--magnetic duality symmetry contains, besides the Maxwell field, additional propagating vector degrees of freedom. Hence it cannot be considered as a duality symmetric action for a {\it single} abelian gauge field.