What is the Homogeneity of our Universe Telling Us?

TL;DR

This paper discusses the cosmic homogeneity problem, its current solutions, and the need for new physics for a definitive deterministic resolution.

Contribution

It critically examines existing explanations for cosmic homogeneity and argues that only radical new physics can provide a true deterministic solution.

Findings

Inflation alleviates but does not fully solve the homogeneity problem.

Probabilistic solutions face interpretational challenges.

A definitive solution requires radical departures from known physics.

Abstract

The universe we observe is homogeneous on super-horizon scales, leading to the ``cosmic homogeneity problem''. Inflation alleviates this problem but cannot solve it within the realm of conservative extrapolations of classical physics. A probabilistic solution of the problem is possible but is subject to interpretational difficulties. A genuine deterministic solution of the homogeneity problem requires radical departures from known physics.