A White Hole Model of the Big Bang

TL;DR

This paper proposes a large white hole model of the universe as an alternative to standard big bang theories, analyzing its inhomogeneities and observational constraints.

Contribution

It introduces a specific Lemaitre-Tolman white hole model and constrains its parameters using observational data, offering a novel inhomogeneous cosmological framework.

Findings

White hole model can fit current observational limits

Predicted Omega value between 0.9999 and 1

Constraints on model parameters from CMB and Hubble flow

Abstract

A model of the universe as a very large white hole provides a useful alternative inhomogeneous theory to pit against the homogeneous standard FLRW big bang models. The white hole would have to be sufficiently large that we can fit comfortably inside the event horizon at the present time, so that the inhomogeneities of space-time are not in contradiction with current observational limits. A specific Lemaitre-Tolman model of a spherically symmetric non-rotating white hole with a few adjustable parameters is investigated. Comparison of calculated anisotropy in the Hubble flow and the CMB against observational limits constrain the parameter space. A Copernican principle would require that we are not too near the centre of the white hole. As an additional constraint this predicts a value of Omega between 0.9999 and 1.