Was there a Big Bang?

TL;DR

This paper introduces a new exact solution in General Relativity with a scalar field that models a universe without a Big Bang, featuring accelerating expansion and naked singularities.

Contribution

It presents a novel one-parameter family of solutions with a Liouville-type metric, expanding the understanding of scalar field cosmologies without initial singularities.

Findings

Solutions describe universe evolution with naked singularities

Existence of solutions with accelerating expansion

Universe can be extended infinitely into the past without a Big Bang

Abstract

New one parameter family of exact solutions in General Relativity with a scalar field is found. The metric is of Liouville type which admits complete separation of variables in the geodesic Hamilton-Jacobi equation. This solution exists for the exponential potential for a scalar field and is invariant with respect to global Lorentz transformations. It describes, in particular, evolution of the space-time with the naked singularity. Solutions corresponding to the naked singularity provide accelerating expansion of the homogeneous and isotropic Universe, and can be smoothly continued along geodesics to infinite past without Big Bang.