Analytic formulae for CMB anisotropy in LTB cosmology

TL;DR

This paper derives analytic formulae to compare LTB void cosmology models with CMB anisotropy observations, enabling tests of these models as alternatives to dark energy-driven acceleration.

Contribution

It provides the first set of analytic formulae for CMB anisotropy in LTB models, facilitating rigorous observational constraints.

Findings

Analytic formulae for CMB anisotropy in LTB models derived

Constraints on observer position within void models established

Enables comparison of LTB models with CMB data

Abstract

The local void model has lately attracted considerable attention since it can explain the present apparent accelerated expansion of the universe without introducing dark energy. However, in order to justify this model as an alternative cosmological model to the standard $\Lambda$CDM model (FLRW universe plus dark energy), one has to test the model by various observations, such as CMB temperature anisotropy, other than the distance-redshift relation of SNIa. For this purpose, we derive some analytic formulae that can be used to rigorously compare consequences of this model with observations of CMB anisotropy and to place constraints on the position of observers in the void model.