Augustine of Hippo's philosophy of time meets general relativity

TL;DR

This paper proposes a cosmological model integrating Augustine of Hippo's philosophical ideas on time with general relativity, addressing homogeneity and entropy issues through a causality-based approach involving a chronology violating region.

Contribution

It introduces a novel cosmological model that combines philosophical concepts of time with relativistic physics, featuring a causality argument and a null hypersurface replacing the traditional Big Bang boundary.

Findings

Model reproduces Augustine's view on time and the Universe's beginning

Causality argument resolves homogeneity and entropy problems

Null hypersurface replaces the spacelike Big Bang boundary

Abstract

A cosmological model is proposed which uses a causality argument to solve the homogeneity and entropy problems of cosmology. In this model a chronology violating region of spacetime causally precedes the remainder of the Universe, and a theorem establishes the existence of time functions precisely outside the chronology violating region. This model is shown to nicely reproduce Augustine of Hippo's thought on time and the beginning of the Universe. In the model the spacelike boundary representing the Big Bang is replaced by a null hypersurface at which the gravitational degrees of freedom are almost frozen while the matter and radiation content is highly homogeneous and thermalized.