Hidden spacetime symmetries and generalized holonomy in M-theory Original Research Article

In M-theory vacua with vanishing 4-form F(4), one can invoke the ordinary Riemannian holonomy H⊂SO(10,1) to account for unbroken supersymmetries n=1, 2, 3, 4, 6, 8, 16, 32. However, the generalized holonomy conjecture, valid for non-zero F(4), can account for more exotic fractions of supersymmetry, in particular 16