Can a void mimic the $\Lambda$ in $\Lambda$CDM?

Abstract

We investigate Lemaître-Tolman-Bondi (LTB) models, whose early time evolution and bang time are homogeneous and the distance - redshift relation and local Hubble parameter are inherited from the $\Lambda$CDM model. We show that the obtained LTB models and the $\Lambda$CDM model predict different relative local expansion rates and that the Hubble functions of the models diverge increasingly with redshift. The LTB models show tension between low redshift baryon acoustic oscillation and supernova observations and including Lyman-$\alpha$ forest or cosmic microwave background observations only accentuates the better fit of the $\Lambda$CDM model compared to the LTB model. The result indicates that additional degrees of freedom are needed to explain the observations, for example by renouncing spherical symmetry, homogeneous bang time, negligible effects of pressure, or the early time homogeneity assumption.

27 pages, 11 figures

References in corpus (8)

• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars
• CMB anisotropies seen by an off-center observer in a spherically symmetric inhomogeneous universe
• Looking the void in the eyes - the kSZ effect in LTB models
• Testing the Void against Cosmological data: fitting CMB, BAO, SN and H0
• Precision cosmology defeats void models for acceleration
• The Cosmic Microwave Background in an Inhomogeneous Universe - why void models of dark energy are only weakly constrained by the CMB
• Accelerating expansion or inhomogeneity? Part 2: Mimicking acceleration with the energy function in the Lema\^ıtre-Tolman model

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• The trouble with Hubble: Local versus global expansion rates in inhomogeneous cosmological simulations with numerical relativity
• Geodesic-light-cone coordinates and the Bianchi I spacetime
• Multiple non-spherical structures from the extrema of Szekeres scalars
• Redshift drift in an inhomogeneous universe: averaging and the backreaction conjecture
• Non-Spherical Szekeres models in the language of Cosmological Perturbations
• Averaged Lemaître-Tolman-Bondi dynamics
• Stephani Cosmology: Entropically Viable But Observationally Challenged
• Observational Constraint on Spherical Inhomogeneity with CMB and Local Hubble Parameter