http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:3467 We show how, for all dimensions and signatures, the most general first-order linear symmetry operator for the massive Dirac equation is given in terms of Killing–Yano tensors. In the massless case the Killing–Yano condition is relaxed to the conformal Killing–Yano generalization. 2010-04-27T05:29:22.093Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:5966 We look at first-order operators taking solutions to the twistor equation to solutions to the Dirac equation. This leads us to an interesting family of conformally-covariant equations for differential forms of arbitrary degree. This family of equations includes the conformally-covariant Laplace equation and the generalised (to middle-forms) Maxwell equation. First-order symmetry operators for this family give us second-order ones for the homogeneous members. We outline how this works in the conformally-flat case. 2010-04-27T04:42:33.695Z ]]>