Classification of Field Equationsfor Weyl and Elko Spinors

A class of field (relativistically invariant) equations is introduced for a wave function consisting of several Weyl spinors. The equations are such that each of these Weyl spinors satisfies the Klein–Gordon equation with the same mass. Subclasses of equations of Majorana type and Dirac type are introduced. It is shown that the known equations for Elko spinors belong to the subclass of Dirac type equations.