Cosmological Model with a Local Void: New Supernova Constraints

TL;DR

This paper investigates a cosmological model featuring a large local void constrained by supernova data, revealing the necessity for more realistic inhomogeneous models or a clumpy universe to fit observations.

Contribution

It introduces constraints on a local void in inhomogeneous cosmological models using recent supernova data, highlighting the need for more realistic or clumpy universe models.

Findings

A large local void (~1 Gpc) is required to fit supernova data.

Previous models with smaller voids (~200 Mpc) are inconsistent with current data.

Clumpy universe models with a low clumpiness parameter can also fit the data.

Abstract

A simple inhomogeneous cosmological model with a local void is constrained with the latest Union supernova compilation. To fit the supernova data, a large local void on the scales of 1 Gpc is found, contrary to the small scales of 200 Mpc in the previous finding. A more realistic inhomogeneous cosmological model may be required to fit the supernova data. Alternatively, a clumpy universe with clumpiness parameter < 1 can fit the supernova data with reduced local void scales.