Symmetry group at future null infinity II: Vector theory

In this paper, we reduce the electromagnetic theory to future null infinity and obtain a vector theory at the boundary. We compute the Poincare flux operators which could be generalized. We quantize the vector theory, and impose normal order on the extended flux operators. It is shown that these flux operators generate the supertranslation and superrotation. When work out the commutators of these operators, we find that a generalized electromagnetic duality operator should be included as the generators to form a closed symmetry algebra.

Automated summary

In this paper, the electromagnetic theory is simplified to future null infinity and a vector theory at the boundary is obtained. The Poincare flux operators are computed and their generalization is discussed. The vector theory is quantized and the extended flux operators are subjected to normal ordering. It is shown that these flux operators generate supertranslations and superrotations. The commutators of these operators reveal the inclusion of a generalized electromagnetic duality operator to form a closed symmetry algebra.