Influence of the Particles Creation on the Flat and Negative Curved FLRW Universes

TL;DR

This paper analyzes how particle creation affects the early dynamics of flat and negative curved FLRW universes, leading to solutions like eternal inflation and curvature-dominated singularities, which naturally address the horizon problem.

Contribution

It introduces a phenomenological approach to particle creation in FLRW universes, revealing significant modifications to early universe dynamics and solutions to the horizon problem.

Findings

Particle creation induces negative pressure affecting early universe evolution.

Solutions include eternal inflation-like states and curvature-dominated singularities.

Horizon problem is naturally resolved in these models.

Abstract

We present a dynamical analysis of the (classical) spatially flat and negative curved Friedmann-Lameitre-Robertson-Walker (FLRW) universes evolving, (by assumption) close to the thermodynamic equilibrium, in presence of a particles creation process, described by means of a realiable phenomenological approach, based on the application to the comoving volume (i. e. spatial volume of unit comoving coordinates) of the theory for open thermodynamic systems. In particular we show how, since the particles creation phenomenon induces a negative pressure term, then the choice of a well-grounded ansatz for the time variation of the particles number, leads to a deep modification of the very early standard FLRW dynamics. More precisely for the considered FLRW models, we find (in addition to the limiting case of their standard behaviours) solutions corresponding to an early universe characterized respectively by an "eternal" inflationary-like birth and a spatial curvature dominated singularity. In both these cases the so-called horizon problem finds a natural solution.