Exploring Parameter Constraints on Quintessential Dark Energy: The Exponential Model

TL;DR

This paper analyzes how well future dark energy experiments can constrain parameters of an exponential scalar field model, comparing results with the DETF parametrization and demonstrating potential to distinguish models from a cosmological constant.

Contribution

It provides a detailed MCMC analysis of exponential dark energy models using simulated DETF data, assessing the constraining power and future experiment capabilities.

Findings

Respective increases in constraining power align with DETF results.

Future Stage 4 data could exclude a cosmological constant at over 3σ for certain models.

Simulated data show potential to distinguish exponential models from ΛCDM.

Abstract

We present an analysis of a scalar field model of dark energy with an exponential potential using the Dark Energy Task Force (DETF) simulated data models. Using Markov Chain Monte Carlo sampling techniques we examine the ability of each simulated data set to constrain the parameter space of the exponential potential for data sets based on a cosmological constant and a specific exponential scalar field model. We compare our results with the constraining power calculated by the DETF using their ``$w_0-w_a$'' parametrization of the dark energy. We find that respective increases in constraining power from one stage to the next produced by our analysis give results consistent with DETF results. To further investigate the potential impact of future experiments, we also generate simulated data for an exponential model background cosmology which can not be distinguished from a cosmological constant at DETF ``Stage 2'', and show that for this cosmology good DETF Stage 4 data would exclude a cosmological constant by better than 3$\sigma$.