Cosmic age test in inhomogeneous cosmological models mimicking $\Lambda$CDM on the light cone

TL;DR

This paper investigates the cosmic age in an inhomogeneous LTB model that mimics $ ext{Lambda}$CDM on the light cone, finding an age estimate inconsistent with some Milky Way observations.

Contribution

It calculates the cosmic age in a reconstructed LTB model matching $ ext{Lambda}$CDM observations, highlighting potential inconsistencies with local galaxy data.

Findings

Cosmic age in the LTB model is less than 11.7 Gyr at 2$\sigma$ confidence.

The age estimate conflicts with some observations of the Milky Way.

The study questions the compatibility of inhomogeneous models with local age measurements.

Abstract

The possibility of reconstructing a spherically symmetric inhomogeneous Lemaitre-Tolman-Bondi (LTB) model with $\Lambda$CDM observations has drawn a lot of attention. Recently, a LTB model having the same luminosity-distance and light-cone mass density as the $\Lambda$CDM model was reconstructed. We calculate the cosmic age at our position in this model, and get the age $t_{LTB}<11.7$Gyr in 2$\sigma$ confidence level from the Seven-Year WMAP observations. This result is inconsistent with some Milky Way observations.