Standard model fermions and K(E10)

Abstract: In recent work arXiv:1412.1715 it was shown how to modify Gell-Mann's proposal for identifying the 48 quarks and leptons of the Standard Model with the 48 spin-1/2 fermions of maximal SO(8) gauged supergravity that remain after the removal of eight Goldstinos, by deforming the residual U(1) symmetry at the SU(3)xU(1) stationary point of N=8 supergravity to also achieve agreement of the electric charge assignments. In this Letter we show that the required deformation, while not in SU(8), does belong to K(E10), the `maximal compact' subgroup of E10 which is a possible candidate symmetry underlying M theory. The incorporation of infinite-dimensional Kac-Moody symmetries of hyperbolic type, apparently unavoidable for the present scheme to work, opens up completely new perspectives on embedding Standard Model physics into a Planck scale theory of quantum gravity.