11. If \ lambda = 0 then the spinor is called a parallel spinor. 12. If \ lambda = 0 then the spinor is called a parallel spinor . 13. These are the left-handed and right-handed Weyl spinor representations. 14. In 8 dimensions there is, projectively, a single pure spinor constraint. 15. However the Dirac spinor representation is not always irreducible. 16. In physics fermions are described by spinor fields and bosons by tensor fields. 17. The extra information in representation theory of groups is provided by the spinor representations. 18. We then say it transforms as a spinor . 19. See spinor for some examples associated with spinor representations of the spin groups and. 20. See spinor for some examples associated with spinor representations of the spin groups and.