A Nonsingular Universe

TL;DR

This paper proposes a modified gravity theory with higher derivatives that ensures all homogeneous solutions are nonsingular, eliminating the traditional big bang and big crunch singularities.

Contribution

It introduces a novel higher derivative effective action for gravity that guarantees nonsingular homogeneous cosmological solutions.

Findings

All homogeneous solutions are nonsingular.

Elimination of big bang and big crunch singularities.

Effective action analogous to relativistic point particle action.

Abstract

We construct an effective action for gravity in which all homogeneous solutions are nonsingular. In particular, there is neither a big bang nor a big crunch. The action is a higher derivative modification of Einstein's theory constructed in analogy to how the action for point particle motion in special relativity is obtained from Newtonian mechanics.