Abstract
Requiring all massless elementary fields to have conformal scaling symmetry removes the conflict between gravitational theory and the quantum theory of elementary particles and fields. Extending this postulate to the scalar field of the Higgs model, dynamical breaking of both gauge and conformal symmetries determines parameters for the interacting fields. In uniform isotropic geometry a modified Friedmann cosmic evolution equation is derived with nonvanishing cosmological constant. Parameters determined by numerical solution are consistent with empirical data for redshifts z ≤ z* = 1090, including luminosity distances for observed type Ia supernovae and peak structure ratios in the cosmic microwave background (CMB). The theory does not require dark matter.