Constructing Phantom Cosmologies from Standard Scalar Field Universes

TL;DR

This paper demonstrates how form-invariance transformations can generate phantom cosmologies from standard scalar field models, including braneworld scenarios, by relating different barotropic indices and using exponential potentials.

Contribution

It introduces a method to construct phantom cosmologies from standard scalar field universes using form-invariance transformations, extending to braneworld modifications.

Findings

Duality between standard and phantom cosmologies established.

Method applies to models with exponential potentials.

Duality persists with braneworld modifications.

Abstract

We illustrate how form-invariance transformations can be used for constructing phantom cosmologies from standard scalar field universes. First, we discuss how to relate two flat Friedmann-Robertson-Walker cosmologies with different barotropic indexes $\gamma$ and $\bar \gamma$. Then, we consider the particular case $\bar \gamma=-\gamma$, and we show that if the matter content is interpreted in terms of self-interacting scalar fields, then the corresponding transformation provides the link between a standard and a phantom cosmology. After that, we illustrate the method by considering models with exponential potentials. Finally, we also show that the mentioned duality persists even if the typical braneworld modifications to the Friedmann equation are considered.