Combined cosmological and solar system constraints on chameleon mechanism
Abstract
The chameleon mechanism appearing in the massive tensor-scalar theory of gravity can effectively reduce locally the nonminimal coupling between the scalar field and matter. This mechanism is invoked to reconcile large-scale departures from general relativity, supposedly accounting for cosmic acceleration, to small-scale stringent constraints on general relativity. In this paper, we carefully investigate this framework on cosmological and solar system scales to derive combined constraints on model parameters, notably by performing a nonambiguous derivation of observables like luminosity distance and local post-Newtonian parameters. The likelihood analysis of type Ia supernovae data and of an admissible domain for the parametrized-post-Newtonian parameters clearly demonstrates that the chameleon mechanism cannot occur in the same region of parameter space as the one necessary to account for cosmic acceleration with the assumed Ratra-Peebles potential and exponential coupling function.
- Publication:
-
Physical Review D
- Pub Date:
- May 2012
- DOI:
- 10.1103/PhysRevD.85.103005
- arXiv:
- arXiv:1111.4784
- Bibcode:
- 2012PhRvD..85j3005H
- Keywords:
-
- 95.36.+x;
- 04.50.Kd;
- 04.80.Cc;
- Dark energy;
- Modified theories of gravity;
- Experimental tests of gravitational theories;
- General Relativity and Quantum Cosmology;
- Astrophysics - Cosmology and Nongalactic Astrophysics
- E-Print:
- revised version, minor changes