Finite cosmology and a CMB cold spot

TL;DR

This paper models the universe as a finite spherical region, predicting observable effects like a CMB cold spot and low multipole suppression, and discusses its geometry and implications for cosmogenesis.

Contribution

It introduces a finite universe model with testable predictions, contrasting with the standard infinite flat universe paradigm.

Findings

Estimated universe radius of at least 50 billion light-years.

Predicted observable CMB cold spot near the universe's edge.

Suggested suppression of low multipoles in the angular power spectrum.

Abstract

The standard cosmological model posits a spatially flat universe of infinite extent. However, no observation, even in principle, could verify that the matter extends to infinity. In this work we model the universe as a finite spherical ball of dust and dark energy, and obtain a lower limit estimate of its mass and present size: the mass is at least 5 x 10^23 solar masses and the present radius is at least 50 Gly. If we are not too far from the dust-ball edge we might expect to see a cold spot in the cosmic microwave background, and there might be suppression of the low multipoles in the angular power spectrum. Thus the model may be testable, at least in principle. We also obtain and discuss the geometry exterior to the dust ball; it is Schwarzschild-de Sitter with a naked singularity, and provides an interesting picture of cosmogenesis. Finally we briefly sketch how radiation and inflation eras may be incorporated into the model.