Universe's Expansion Puts Limits On The Cosmic Time ScaleVariations Of Gravitational And Cosmological `Constants'

Limits on cosmic time scale variations of gravitational and cosmological `constants' are studied. The study is based on a function which can measure the temporal variation of the magnitude of the gradient of any scalar field defined inside a medium exposed to a gravitational field. The cosmic time dependent scalar fields are taken to be the gravitational and cosmological `constants'. The medium; in which those scalar fields are defined; is taken to be the spatially perturbed Friedman-Robertson-Walker (FRW) expanding universe. This revised version was published online in July 2006 with corrections to the Cover Date.