Cosmic microwave background constraints on the strong equivalence principle
Abstract
We study the effect of a violation of the strong equivalence principle (SEP) on the cosmic microwave background (CMB). Such a violation would modify the weight of baryons in the primordial gravitational potentials and hence their impact in the establishment of the photon-baryon plasma acoustic oscillations before recombination. This cosmological Nordtvedt effect alters the odd peaks height of the CMB temperature anisotropy power spectrum. A gravitational baryonic mass density of the Universe may already be inferred at the first peak scale from the analysis of Wilkinson microwave anisotropy probe (WMAP) data. Experimental constraints on a primordial SEP violation are derived from a comparison with the Universe’s inertial baryonic mass density measured either in a full analysis of the CMB, or in the framework of the standard big bang nucleosynthesis (BBN).
- Publication:
-
Physical Review D
- Pub Date:
- November 2004
- DOI:
- 10.1103/PhysRevD.70.103528
- arXiv:
- arXiv:astro-ph/0407208
- Bibcode:
- 2004PhRvD..70j3528B
- Keywords:
-
- 98.80.Es;
- 04.80.Cc;
- 98.70.Vc;
- 98.80.Ft;
- Observational cosmology;
- Experimental tests of gravitational theories;
- Background radiations;
- Origin formation and abundances of the elements;
- Astrophysics;
- General Relativity and Quantum Cosmology
- E-Print:
- Version accepted for publication in Phys. Rev. D, 8 pages, Revtex 4