Constraining LTB models with JLA supernovae and BAO

TL;DR

This paper constrains Lemaître-Tolman-Bondi models using supernovae and BAO data, improving calibration methods and analyzing the impact of different parameter estimation approaches.

Contribution

It introduces refined calibration techniques for supernovae in inhomogeneous backgrounds and compares two parameter estimation methods in LTB model constraints.

Findings

BAO+SNIa data provide stringent tests for LTB models.

Calibration in inhomogeneous backgrounds improves model constraints.

Differences between $^2$ and likelihood approaches are demonstrated.

Abstract

In the present work we constrain three different profiles of a Lema\^itre-Tolman-Bondi model using supernovae type Ia and baryon acoustic oscillation data. We improve common practice in the literature by carefully calibrating the supernovae in the appropriate inhomogeneous background dynamics. In addition, we address subtle issues in order to propagate the primordial BAO scale to present epoch. The combined analysis of BAO+SNIa offers a stringent test for these models. We use two distinct parameter estimation approaches, namely, the $\chi^2$ and the complete likelihood functional. It has been argued that these two approaches are not equivalent and indeed our analysis shows a specific example of their departure.