Quaternionic and octonionic spinors
  Quaternionic and octonionic spinors are introduced and their fundamental properties (such as the space-times supporting them) are reviewed. The conditions for the existence of their associated Dirac equations are analyzed. Quaternionic and octonionic supersymmetric algebras defined in terms of such spinors are constructed. Specializing to the D=11-dimensional case, the relation of both the quaternionic and the octonionic supersymmetries with the ordinary M-algebra are discussed. 
Francesco Toppan