2009/09/30 by Tommaso Giannantonio, T. Giannantonio, Matteo Martinelli +4 · 4 citations
Physics and Astronomy · #Advanced Differential Geometry Research #Anisotropy #Astrophysics #Black Holes and Theoretical Physics #Cosmic microwave background #Cosmology #Cosmology and Gravitation Theories #Dark energy #Hubble's law #Markov chain Monte Carlo #Monte Carlo method #Particle physics #Physics #Planck #Quantum mechanics #Theoretical physics #Yukawa potential #astro-ph.CO
paper · pdf · doi:10.1088/1475-7516/2010/04/030
published as JCAP 1004:030,2010 · 8 pages, 3 figures. Minor modifications, version accepted by JCAP
arxiv created 2010/04/15 · openalex publication_date 2010/04/28 · arxiv updated 2014/11/20 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We study the effects of modified theories of gravity on the cosmic microwave background (CMB) anisotropies power spectrum, and in particular on its large scales, where the integrated Sachs-Wolfe (ISW) effect is important. Starting with a general parametrisation, we then specialise to f ( R ) theories and theories with Yukawa-type interactions between dark matter particles. In these models, the evolution of the metric potentials is altered, and the contribution to the ISW effect can differ significantly from that in the standard model of cosmology. We proceed to compare these predictions with observational data for the CMB and the ISW, performing a full Monte Carlo Markov chain (MCMC) analysis. In the case of f ( R ) theories, the result is an upper limit on the lengthscale associated to the extra scalar degree of freedom characterising these theories. With the addition of data from the Hubble diagram of Type Ia supernovae, we obtain an upper limit on the lengthscale of the theory of B 0 < 0.4, or correspondingly λ 1 < 1900 Mpc/h at 95% c.l. improving previous CMB constraints. For Yukawa-type models we get a bound on the coupling 0.75 < β 1 < 1.25 at the 95% c.l. We also discuss the implications of the assumed priors on the estimation of modified gravity parameters, showing that a marginally less conservative choice improves the f ( R ) constraints to λ 1 < 1400 Mpc/h, corresponding to B 0 < 0.2 at 95% c.l.