Uncertainty on w from large-scale structure

Abstract

We find that if we live at the center of an inhomogeneity with total density contrast of roughly 0.1, dark energy is not a cosmological constant at 95% confidence level. Observational constraints on the equation of state of dark energy, w, depend strongly on the local matter density around the observer. We model the local inhomogeneity with an exact spherically symmetric solution which features a pressureless matter component and a dark-energy fluid with constant equation of state and negligible sound speed, that reaches a homogeneous solution at finite radius. We fit this model to observations of the local expansion rate, distant supernovae and the cosmic microwave background. We conclude that the possible uncertainty from large-scale structure has to be taken into account if one wants to progress towards not just precision but also accurate cosmology.

13 pages, 10 figures; v2: matches version accepted for publication in MNRAS; v3: corrects latex problem. Numerical module available at http://web.physik.rwth-aachen.de/download/valkenburg/

References in corpus (23)

• Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
• Imperfect Dark Energy from Kinetic Gravity Braiding
• The Hubble Constant: A Summary of the HST Program for the Luminosity Calibration of Type Ia Supernovae by Means of Cepheids
• The Effective Theory of Quintessence: the w<-1 Side Unveiled
• On cosmological observables in a swiss-cheese universe
• Dynamical Dark Energy or Simply Cosmic Curvature?
• Local Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies I
• Examining the evidence for dynamical dark energy
• Looking the void in the eyes - the kSZ effect in LTB models
• Testing the Void against Cosmological data: fitting CMB, BAO, SN and H0
• Light-cone averages in a swiss-cheese universe
• Scalar Perturbations on Lemaitre-Tolman-Bondi Spacetimes
• Precision cosmology defeats void models for acceleration
• Local Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies: The Effect of a Cosmological Constant
• Dark energy with non-adiabatic sound speed: initial conditions and detectability
• Unified Dark Matter Scalar Field Models
• Linear kinetic Sunyaev-Zel'dovich effect and void models for acceleration
• Swiss Cheese and a Cheesy CMB
• Observational constraints on the LLTB model
• Large-scale inhomogeneities may improve the cosmic concordance of supernovae
• LTB solutions in Newtonian gauge: from strong to weak fields
• The Cold Spot as a Large Void: Rees-Sciama effect on CMB Power Spectrum and Bispectrum
• Cosmology when living near the Great Attractor