(An)isotropy of the Hubble diagram: comparing hemispheres

Abstract

We test the isotropy of the Hubble diagram. At small redshifts, this is possible without assumptions on the cosmic inventory and provides a fundamental test of the cosmological principle. At higher redshift we check for the self-consistency of the LambdaCDM model. At small redshifts, we use public supernovae (SNe) Ia data to determine the deceleration parameter q_0 and the SN calibration on opposite hemispheres. For the complete data sets we fit Omega_M and the SN calibration on opposite hemispheres. A statistically significant anisotropy of the Hubble diagram at redshifts z < 0.2 is discovered (> 95% C.L.). While data from the North Galactic hemisphere favour the accelerated expansion of the Universe, data from the South Galactic hemisphere are not conclusive. The hemispheric asymmetry is maximal toward a direction close to the equatorial poles. The discrepancy between the equatorial North and South hemispheres shows up in the SN calibration. For the LambdaCDM model fitted to all available SNe, we find the same asymmetry. The alignment of discrepancies between hemispheric Hubble diagrams with the equatorial frame seems to point toward a systematic error in the SN search, observation, analysis or data reduction. We also find that our model independent test cannot exclude the case of the deceleration of the expansion at a statistically significant level.

13 pages, 8 figures; several corrections - conclusions unchanged; matches published version

References in corpus (9)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Improved Distances to Type Ia Supernovae with Multicolor Light Curve Shapes: MLCS2k2
• The Hubble Constant: A Summary of the HST Program for the Luminosity Calibration of Type Ia Supernovae by Means of Cepheids
• The Uncorrelated Universe: Statistical Anisotropy and the Vanishing Angular Correlation Function in WMAP Years 1-3
• Correlated Fluctuations in Luminosity Distance and the (Surprising) Importance of Peculiar Motion in Supernova Surveys
• Is there Evidence for a Hubble bubble? The Nature of Type Ia Supernova Colors and Dust in External Galaxies
• Dipole of the luminosity distance: a direct measure of H(z)
• Anisotropy in the Hubble constant as observed in the HST Extragalactic Distance Scale Key Project results
• Large-Scale Bulk Motions Complicate the Hubble Diagram

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