Exploring Parameter Constraints on Quintessential Dark Energy: the Albrecht-Skordis model

TL;DR

This paper investigates how future dark energy experiments, using simulated data, can constrain the parameters of the Albrecht-Skordis scalar field model, considering spatial curvature, and demonstrates the model's distinguishability from a cosmological constant.

Contribution

It introduces a comprehensive analysis of the Albrecht-Skordis dark energy model using Monte Carlo methods and simulated future data, including spatial curvature effects.

Findings

Future experiments can significantly constrain AS model parameters.

The AS model's equations of state can differ markedly from simple parametrizations.

Results are consistent with DETF findings despite model differences.

Abstract

We consider the effect of future dark energy experiments on ``Albrecht-Skordis'' (AS) models of scalar field dark energy using the Monte-Carlo Markov chain method. We deal with the issues of parameterization of these models, and have included spatial curvature as a parameter, finding it to be important. We use the Dark Energy Task Force (DETF) simulated data to represent future experiments and report our results in the form of likelihood contours in the chosen parameter space. Simulated data is produced for cases where the background cosmology has a cosmological constant, as well as cases where the dark energy is provided by the AS model. The latter helps us demonstrate the power of DETF Stage 4 data in the context of this specific model. Though the AS model can produce equations of state functions very different from what is possible with the $w_0-w_a$ parametrization used by the DETF, our results are consistent with those reported by the DETF.