Relativistic Cosmology with Zero Deceleration Parameter

The possibility that the deceleration parameter q might be a null constant is discussed; such possibilitiy is interesting because solves the horizon problem and the flatness problem with no need of inflation. A simple way to get q = const = 0 is explored: the way assumes Einstein's field equations without cosmological term and introduces a massless scalar field V with negative energy density. Both in the early and in the present universe one finds the Whitrow-Randall relation Gut² = const 1 G gravitational coupling, u mass-energy density, t cosmic time). The interaction between the V-field and the ordinary matter is briefly discussed; as possible consequence of this interaction the true value of the Hubble parameter might be one half the observed value. This revised version was published online in July 2006 with corrections to the Cover Date.