Constraining dark sector perturbations II: ISW and CMB lensing tomography

Abstract

Any Dark Energy (DE) or Modified Gravity (MG) model that deviates from a cosmological constant requires a consistent treatment of its perturbations, which can be described in terms of an effective entropy perturbation and an anisotropic stress. We have considered a recently proposed generic parameterisation of DE/MG perturbations and compared it to data from the Planck satellite and six galaxy catalogues, including temperature-galaxy (Tg), CMB lensing-galaxy and galaxy-galaxy (gg) correlations. Combining these observables of structure formation with tests of the background expansion allows us to investigate the properties of DE/MG both at the background and the perturbative level. Our constraints on DE/MG are mostly in agreement with the cosmological constant paradigm, while we also find that the constraint on the equation of state w (assumed to be constant) depends on the model assumed for the perturbation evolution. We obtain $w=-0.92_{-0.16}^{+0.20}$ (95% CL; CMB+gg+Tg) in the entropy perturbation scenario; in the anisotropic stress case the result is $w=-0.86_{-0.16}^{+0.17}$. Including the lensing correlations shifts the results towards higher values of w. If we include a prior on the expansion history from recent Baryon Acoustic Oscillations (BAO) measurements, we find that the constraints tighten closely around $w=-1$, making it impossible to measure any DE/MG perturbation evolution parameters. If, however, upcoming observations from surveys like DES, Euclid or LSST show indications for a deviation from a cosmological constant, our formalism will be a useful tool towards model selection in the dark sector.

25 pages, 8 figures; minor update for consistency with version accepted by JCAP (13/01/2015)

References in corpus (21)

• Supernova Constraints and Systematic Uncertainties from the First 3 Years of the Supernova Legacy Survey
• Imperfect Dark Energy from Kinetic Gravity Braiding
• A Parameterized Post-Friedmann Framework for Modified Gravity
• Correlation of CMB with large-scale structure: I. ISW Tomography and Cosmological Implications
• Distinguishing Modified Gravity from Dark Energy
• Combined analysis of the integrated Sachs-Wolfe effect and cosmological implications
• Searching for modified growth patterns with tomographic surveys
• Crossing the Phantom Divide with Parameterized Post-Friedmann Dark Energy
• Testing gravity with CAMB and CosmoMC
• Current constraints on the cosmic growth history
• The Parameterized Post-Friedmann Framework for Theories of Modified Gravity: Concepts, Formalism and Examples
• Effective Field Theory of Cosmic Acceleration: constraining dark energy with CMB data
• Observables and unobservables in dark energy cosmologies
• Probing modifications of General Relativity using current cosmological observations
• Parametrized Post-Friedmann Signatures of Acceleration in the CMB
• The significance of the integrated Sachs-Wolfe effect revisited
• A Measurement of the Correlation of Galaxy Surveys with CMB Lensing Convergence Maps from the South Pole Telescope
• Hidden Negative Energies in Strongly Accelerated Universes
• Consistent perturbations in an imperfect fluid
• Cosmological Perturbations in Elastic Dark Energy Models
• Probing Modified Gravity Theories with ISW and CMB Lensing

Cited by in corpus (1)

• Distinguishing interacting dark energy from wCDM with CMB, lensing, and baryon acoustic oscillation data