Large-scale inhomogeneities may improve the cosmic concordance of supernovae

TL;DR

This paper investigates how large-scale inhomogeneities and weak lensing effects influence supernova data analysis, showing they can enhance the agreement with the standard cosmological model.

Contribution

It introduces a method to incorporate lensing effects from inhomogeneities into supernova data analysis, improving the fit to the flat LCDM model.

Findings

Lensing effects shift best-fit parameters towards the concordance model.

Inclusion of inhomogeneities improves consistency with CMB and BAO constraints.

Lensing can significantly influence cosmological parameter estimation.

Abstract

We reanalyze the supernovae data from the Union Compilation including the weak lensing effects caused by inhomogeneities. We compute the lensing probability distribution function for each background solution described by the parameters Omega_M, Omega_L and w in the presence of inhomogeneities, approximately modeled with a single-mass population of halos. We then perform a likelihood analysis in the space of FLRW-parameters and compare our results with the standard approach. We find that the inclusion of lensing can move the best-fit model significantly towards the cosmic concordance of the flat LCDM model, improving the agreement with the constraints coming from the cosmic microwave background and baryon acoustic oscillations.