The $m$-$z$ relation for Type Ia supernovae: safety in numbers or safely without worry?

Abstract

The $m$-$z$ relation for Type Ia supernovae is compatible with the cosmological concordance model if one assumes that the Universe is homogeneous, at least with respect to light propagation. This could be due to the density along each line of sight being equal to the overall cosmological density, or to `safety in numbers', with variation in the density along all lines of sight averaging out if the sample is large enough. Statistical correlations (or lack thereof) between redshifts, residuals (differences between the observed distance moduli and those calculated from the best-fitting cosmological model), and observational uncertainties suggest that the former scenario is the better description, so that one can use the traditional formula for the luminosity distance safely without worry.

5 pages, 6 figures, accepted for publication in Monthly Notices of the Royal Astronomical Society (includes small changes made while checking the proofs). Related information available at http://www.multivax.de:8000/helbig/research/publications/info/etasnia2.html

References in corpus (4)

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• Improved Constraints on the Acceleration History of the Universe and the Properties of the Dark Energy
• On the Bias of the Distance-Redshift Relation from Gravitational Lensing
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Cited by in corpus (3)

• Mapping the inhomogeneous Universe with Standard Sirens: Degeneracy between inhomogeneity and modified gravity theories
• Understanding the Dyer-Roeder approximation as a consequence of local cancellations of projected shear and expansion rate fluctuations
• Incorporating Astrophysical Systematics into a Generalized Likelihood for Cosmology with Type Ia Supernovae