Cosmological constraints on f(R) acceleration models
Abstract
Models which accelerate the expansion of the universe through the addition of a function of the Ricci scalar f(R) leave a characteristic signature in the largescale structure of the universe at the Compton wavelength scale of the extra scalar degree of freedom. We search for such a signature in current cosmological data sets: the WMAP cosmic microwave background (CMB) power spectrum, Supernovae Legacy Survey supernovae distance measures, the Sloan Digital Sky Survey luminous red galaxy power spectrum, and galaxyCMB angular correlations. Because of theoretical uncertainties in the nonlinear evolution of f(R) models, the galaxy power spectrum conservatively yields only weak constraints on the models despite the strong predicted signature in the linear matter power spectrum. Currently the tightest constraints involve the modification to the integrated SachsWolfe effect from growth of gravitational potentials during the acceleration epoch. This effect is manifest for large Compton wavelengths in enhanced low multipole power in the CMB and anticorrelation between the CMB and tracers of the potential. They place a bound on the Compton wavelength of the field to be less than of order the Hubble scale.
 Publication:

Physical Review D
 Pub Date:
 September 2007
 DOI:
 10.1103/PhysRevD.76.063517
 arXiv:
 arXiv:0706.2399
 Bibcode:
 2007PhRvD..76f3517S
 Keywords:

 98.80.Cq;
 Particletheory and fieldtheory models of the early Universe;
 Astrophysics;
 General Relativity and Quantum Cosmology
 EPrint:
 8 pages, 7 figures