Stokes and skyrmion tensors with application to non-Cartesian coordinates

Abstract: We replace the familiar Stokes vector by a tensor. This enables us to derive the skyrmion field as a tensor quantity. The advantage we obtain is the freedom to work with non-Cartesian coordinates, including polar coordinates. An expression of optical skyrmions in terms of cylindrical coordinates should simplify the descriptions of their propagation and focussing. We reveal a fundamental electromagnetic source of a skyrmion field in the form of radiation by an oscillating dipole.