New constraints on parametrised modified gravity from correlations of the CMB with large scale structure

Abstract

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 SachsWolfe (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 B0 < 0.4, or correspondingly λ1 < 1900 Mpc/h at 95% c.l. improving previous CMB constraints. For Yukawa-type models we get a bound on the coupling 0.75 < β1 < 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 λ1 < 1400 Mpc/h, corresponding to B0 < 0.2 at 95% c.l.

Beyond the cosmological standard model

“…Scalar radiation must be accounted for in future high precision tests that use stellar pulsations or explosions, and may also provide additional tests [894]. Figure 13: Limits on chameleon theories coming from astrophysical [322,859,860] and cosmological [340,895,896] probes. The x-axis gives the range of length scales probed by particular experiments.…”

“…Further, specific MG models can produce both scale and redshift-dependent growth that in principle distinguishes them from dark energy models, given the same expansion history. Cosmological parameter analyses to test MG theories have been performed by several authors [340,884,895,896,903,[908][909][910][911][912][913]. Specific studies to determine the cosmological impact of galileon theories and to constrain model parameters appear in [265,[914][915][916][917][918][919][920].…”

Cosmological hints of modified gravity?

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]) have constrained possible deviations of the evolution of perturbations with respect to the ΛCDM model, by parametrizing the gravitational potentials Φ and Ψ and their linear combinations. Considering the parameter Σ, that modifies the lensing/Weyl potential given by the sum of the Newtonian and curvature potentials Ψ + Φ, the analysis of [3] reported the current value of Σ 0 − 1 = 0.28 ± 0.15 at 68% from Planck CMB temperature data, i.e.…”

Kinetic Sunyaev-Zel’dovich effect in modified gravity

“…In particular, viable fðRÞ models have been constrained with secondary CMB anisotropies, such as CMB lensing, the integrated Sachs-Wolfe effect [7,8] and its cross-correlation with galaxy density [9,10], galaxy cluster abundances [11][12][13] and profiles [14,15], galaxy power spectrum [16,17], redshift-space distortions from spectroscopic surveys [18][19][20], weak gravitational lensing [21,22], 21-cm intensity mapping [23], and dwarf galaxies [24,25].…”