Local void vs dark energy: confrontation with WMAP and type Ia supernovae

  title={Local void vs dark energy: confrontation with WMAP and type Ia supernovae},
  author={Stephon H. S. Alexander and Tirthabir Biswas and Alessio Notari and Deepak Vaid},
  journal={Journal of Cosmology and Astroparticle Physics},
It is now a known fact that if we happen to be living in the middle of a large underdense region, then we will observe an ``apparent acceleration'', even when any form of dark energy is absent. In this paper, we present a ``Minimal Void'' scenario, i.e. a ``void'' with minimal underdensity contrast (of about -0.4) and radius (~ 200−250 Mpc/h) that can, not only explain the supernovae data, but also be consistent with the 3-yr WMAP data. We also discuss consistency of our model with various… 

Constraints on large-scale inhomogeneities from WMAP5 and SDSS: confrontation with recent observations

Measurements of the Type Ia supernovae Hubble diagram which suggest that the Universe is accelerating due to the effect of dark energy may be biased because we are located in a 200–300 Mpc underdense

Reconciling the local void with the CMB

In the standard cosmological model, the dimming of distant Type Ia supernovae is explained by invoking the existence of repulsive ''dark energy'' which is causing the Hubble expansion to accelerate.

Testing the void against cosmological data: fitting CMB, BAO, SN and H0

In this paper, instead of invoking Dark Energy, we try and fit various cosmological observations with a large Gpc scale under-dense region (Void) which is modeled by a Lema?tre-Tolman-Bondi metric

Precision cosmology defeats void models for acceleration

The suggestion that we occupy a privileged position near the center of a large, nonlinear, and nearly spherical void has recently attracted much attention as an alternative to dark energy. Putting

Observational constraints on the ΛLTB model

We directly compare the concordance ΛCDM model to the inhomogeneous matter-only alternative represented by LTB void models. To achieve a ``democratic'' confrontation we explore ΛLTB models with

Observational constraints on the ?LTB model

We directly compare the concordance ?CDM model to the inhomogeneous matter-only alternative represented by LTB void models. To achieve a ``democratic'' confrontation we explore ?LTB models with

Distinguishing between void models and dark energy with cosmic parallax and redshift drift

Two recently proposed techniques, involving the measurement of the cosmic parallax and redshift drift, provide novel ways of directly probing (over a time span of several years) the background metric

Supernovae observations in a 'meatball' universe with a local void

We study the impact of cosmic inhomogeneities on the interpretation of observations. We build an inhomogeneous universe model without dark energy that can confront supernova data and yet is

A (giant) void is not mandatory to explain away dark energy with a Lemaître-Tolman model

Context. Lemaitre-Tolman (L-T) toy models with a central observer have been used to study the effect of large scale inhomogeneities on the SN Ia dimming. Claims that a giant void is mandatory to

Virialisation-induced curvature as a physical explanation for dark energy

The geometry of the dark energy and cold dark matter dominated cosmological model (LambdaCDM) is commonly assumed to be given by a Friedmann-Lemaitre-Robertson-Walker (FLRW) metric, i.e. it assumes



Multiple inflation and the WMAP 'glitches' II. Data analysis and cosmological parameter extraction

Detailed analyses of the WMAP data indicate possible oscillatory features in the primordial curvature perturbation, which moreover appears to be suppressed beyond the present Hubble radius. Such

An alternative to the cosmological 'concordance model'

Precision measurements of the cosmic microwave background by WMAP are believed to have established a flat $\Lambda$-dominated universe, seeded by nearly scale-invariant adiabatic primordial

Observational Constraints on the Nature of Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey

We present constraints on the dark energy equation-of-state parameter, w = P/(ρc2), using 60 SNe Ia from the ESSENCE supernova survey. We derive a set of constraints on the nature of the dark energy

CMB anisotropies seen by an off-center observer in a spherically symmetric inhomogeneous universe

The current authors have previously shown that inhomogeneous, but spherically symmetric universe models containing only matter can yield a very good fit to the SNIa data and the position of the first

Large-scale galaxy correlations as a test for dark energy

We have shown earlier that, contrary to popular belief, Einstein-de Sitter (E-deS) models can still fit the WMAP data on the cosmic microwave background provided one adopts a low Hubble constant and

Fossil H ii regions: self-limiting star formation at high redshift

Recent results from the Wilkinson Microwave Anisotropy Probe (WMAP) satellite suggest that the intergalactic medium (IGM) was significantly reionized at redshifts as high as z ∼ 17. At this early

Implications of WMAP observations on the Population III star formation processes

In an earlier paper (Cen 2003) we pointed out the strong likelihood for the universal reionization to occur twice, giving rise to a larger Thomson optical depth. Here we perform a more focused

Analyses of Type Ia Supernova Data in Cosmological Models with a Local Void

The data for type Ia supernovae obtained by the High-z SN Search Team and Supernova Cosmology Project are analyzed using inhomogeneous cosmological models with a local void on scales of about 200

Scalar perturbations on Lemaître-Tolman-Bondi spacetimes

In recent years there has been growing interest in verifying the horizon-scale homogeneity of the Universe that follows from applying the Copernican principle to the observed isotropy. This program

‘Swiss-cheese’ inhomogeneous cosmology and the dark energy problem

We study an exact Swiss-cheese model of the universe, where inhomogeneous LTB patches are embedded in a flat FLRW background, in order to see how observations of distant sources are affected. We