A dynamical dark energy model with a given luminosity distance

TL;DR

This paper proposes a scalar field dark energy model with a specified luminosity distance, analyzing its evolution and comparing it with observational data, revealing differences from the standard Lambda-CDM model in the timing of cosmic acceleration.

Contribution

It introduces a scalar field dark energy model with a predetermined luminosity distance and derives its evolution, contrasting it with standard cosmological models.

Findings

The model's evolution significantly differs from solutions ignoring matter.

The universe begins accelerating at a higher red-shift than in Lambda-CDM.

The model fits BAO and CMB data to determine parameters.

Abstract

It is assumed that the current cosmic acceleration is driven by a scalar field, the Lagrangian of which is a function of the kinetic term only, and that the luminosity distance is a given function of the red-shift. Upon comparison with Baryon Acoustic Oscillations (BAOs) and Cosmic Microwave Background (CMB) data the parameters of the models are determined, and then the time evolution of the scalar field is determined by the dynamics using the cosmological equations. We find that the solution is very different than the corresponding solution when the non-relativistic matter is ignored, and that the universe enters the acceleration era at larger red-shift compared to the standard $\Lambda CDM$ model.