Coupled oscillators as models of phantom and scalar field cosmologies

TL;DR

This paper investigates a toy model of phantom cosmology using coupled oscillators, compares it with exact phase space models of scalar fields, and explores the dynamics of minimally coupled phantom systems.

Contribution

It introduces a simplified oscillator-based model for phantom cosmology and compares its dynamics with more complex scalar field models, providing insights into their similarities and differences.

Findings

The toy oscillator model captures key features of phantom cosmology.

Exact phase space analysis reveals the dynamical behavior of scalar field models.

Comparison shows both similarities and differences between toy and realistic models.

Abstract

We study a toy model for phantom cosmology recently introduced in the literature and consisting of two oscillators, one of which carries negative kinetic energy. The results are compared with the exact phase space picture obtained for similar dynamical systems describing, respectively, a massive canonical scalar field conformally coupled to the spacetime curvature, and a conformally coupled massive phantom. Finally, the dynamical system describing exactly a minimally coupled phantom is studied and compared with the toy model.