Abstract
We present observational constraints on a scalar-tensor gravity theory by test for the CMB anisotropy spectrum. We compare the WMAP temperature power spectrum with the harmonic attractor model, in which the scalar field has its harmonic effective potential with a curvature in the Einstein conformal frame and the theory relaxes toward Einstein gravity with time. We find that the present value of the scalar coupling, i.e., the present level of deviation from Einstein gravity is bounded to be smaller than and for This constraint is much stronger than the bound from the solar system experiments for large models, i.e., and 0.3 in and limits, respectively. Furthermore, within the framework of this model, the variation of the gravitational constant at the recombination epoch is constrained as and
- Received 12 November 2003
DOI:https://doi.org/10.1103/PhysRevD.69.083512
©2004 American Physical Society