Homoclinic Chaos in Axisymmetric Bianchi-IX cosmological models with an "ad hoc" quantum potential

TL;DR

This paper investigates how adding a quantum-inspired potential to an axisymmetric Bianchi IX cosmological model induces homoclinic chaos, leading to complex dynamics such as chaotic escape to inflation and bouncing near singularities.

Contribution

It introduces a quantum potential into the Bianchi IX model and analyzes its impact on the phase space, revealing chaotic behavior through homoclinic crossings of invariant manifolds.

Findings

Quantum potential restricts dynamics to positive scale factors

Homoclinic crossings indicate chaos in the model

Chaotic escape to inflation and bouncing near singularity

Abstract

In this work we study the dynamics of the axisymmetric Bianchi IX cosmological model with a term of quantum potential added. As it is well known this class of Bianchi IX models are homogeneous and anisotropic with two scale factors, $A(t)$ and $B(t)$, derived from the solution of Einstein's equation for General Relativity. The model we use in this work has a cosmological constant and the matter content is dust. To this model we add a quantum-inspired potential that is intended to represent short-range effects due to the general relativistic behavior of matter in small scales and play the role of a repulsive force near the singularity. We find that this potential restricts the dynamics of the model to positive values of $A(t)$ and $B(t)$ and alters some qualitative and quantitative characteristics of the dynamics studied previously by several authors. We make a complete analysis of the phase space of the model finding critical points, periodic orbits, stable/unstable manifolds using numerical techniques such as Poincar\'e section, numerical continuation of orbits and numerical globalization of invariant manifolds. We compare the classical and the quantum models. Our main result is the existence of homoclinic crossings of the stable and unstable manifolds in the physically meaningful region of the phase space (where both $A(t)$ and $B(t)$ are positive), indicating chaotic escape to inflation and bouncing near the singularity.