THE GRAVITATIONAL SECTOR IN THE CONNES-LOTT FORMULATION OF THE STANDARD MODEL

We studied the Riemannian aspect and the Hilbert-Einstein gravitational action of the noncommutative geometry underlying the Connes-Lott construction of the action functional of the standard model. This geometry involves a two-sheeted, Euclidian space-time. We show that if we require the space of forms to be locally isotropic and the Higgs scalar to be dynamical, then the Riemannian metrics on the two sheets of Euclidian space-time must be identical. We also show that the distance function between the two sheets is determined by a single, real scalar held whose vacuum expectation value (VEV) sets the weak scale. (C) 1995 American Institute of Physics.