Brane cosmology with a van der Waals equation of state

TL;DR

This paper explores the evolution of a brane universe with a van der Waals fluid, revealing three distinct acceleration phases influenced by different effective components, including scalar-like behavior, matter, radiation, and a cosmological constant.

Contribution

It introduces a novel brane cosmology model using a van der Waals equation of state to describe the cosmological fluid, capturing multiple acceleration phases.

Findings

Initial accelerated epoch with scalar field behavior

Decelerated period with matter and radiation contributions

Current accelerated phase driven by a cosmological constant

Abstract

The evolution of a Universe confined onto a 3-brane embedded in a five-dimensional space-time is investigated where the cosmological fluid on the brane is modeled by the van der Waals equation of state. It is shown that the Universe on the brane evolves in such a manner that three distinct periods concerning its acceleration field are attained: (a) an initial accelerated epoch where the van der Waals fluid behaves like a scalar field with a negative pressure; (b) a past decelerated period which has two contributions, one of them is related to the van der Waals fluid which behaves like a matter field with a positive pressure, whereas the other contribution comes from a term of the Friedmann equation on the brane which is inversely proportional to the scale factor to the fourth power and can be interpreted as a radiation field, and (c) a present accelerated phase due to a cosmological constant on the brane.