In this paper, a novel conserved Lorentz covariant tensor, termed the helicity tensor, is introduced in Maxwell theory. The conservation of the helicity tensor expresses the conservation laws contained in the helicity array, introduced by Cameron et al. (2012), including helicity, spin, as well as the spin-flux or infra-zilch. The Lorentz covariance of the helicity tensor is in contrast to previous formulations of the helicity hierarchy of conservation laws, which required the non-Lorentz covariant transverse gauge. The helicity tensor is shown to arise as a Noether current for a variational symmetry of a duality-symmetric Lagrangian for Maxwell theory. This symmetry transformation generalizes the duality symmetry and includes the symmetry underlying the conservation of the spin part of the angular momentum.

在本文中，麦克斯韦理论引入了一种新的守恒洛伦兹协变张量，称为螺旋张量。螺旋度张量的守恒表达了螺旋度数组中包含的守恒律，由 Cameron 等人引入。(2012)，包括螺旋度、自旋以及自旋通量或 infra-zilch。螺旋度张量的洛伦兹协方差与之前的守恒定律的螺旋度等级公式形成对比，后者需要非洛伦兹协变横向规范。螺旋张量被证明是作为麦克斯韦理论的对偶对称拉格朗日变分对称性的诺特电流产生的。这种对称变换概括了对偶对称性，并包括角动量自旋部分守恒的对称性。