Is $w\ne -1$ evidence for a dynamical dark energy equation of state ?

Abstract

Current constraints on the dark energy equation of state parameter, $w$, are expected to be improved by more than one order of magnitude in the next decade. If $|w-1| \gsim 0.01$ around the present time, but the dark energy dynamics is sufficiently slow, it is possible that future constraints will rule out a cosmological constant while being consistent with a time-independent equation of state parameter. In this paper, we show that although models with such behavior can be constructed, they do require significant fine-tuning. Therefore, if the observed acceleration of the Universe is induced by a dark energy component, then finding $w\ne -1$ would, on its own, constitute very strong evidence for a dynamical dark energy equation of state.

arXiv comment5 pages, 2 figures

References in corpus (16)

• Dynamics of dark energy
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Generalized Chaplygin Gas, Accelerated Expansion and Dark Energy-Matter Unification
• Dark Energy and the Accelerating Universe
• Perturbations in k-inflation
• Unification of Dark Matter and Dark Energy: the Inhomogeneous Chaplygin Gas
• The Cosmology of Generalized Modified Gravity Models
• Detecting Dark Energy in Orbit -- the Cosmological Chameleon
• Is the Dark Matter a Solid?
• Adiabatic instability in coupled dark energy-dark matter models
• The $\Lambda \mathrm{CDM}$ Limit of the Generalized Chaplygin Gas Scenario
• Dynamics of domain wall networks with junctions
• Frustrated Expectations: Defect Networks and Dark Energy
• Linear and non-Linear Instabilities in Unified Dark Energy Models
• Dynamics of perfect fluid Unified Dark Energy models
• Clustering Properties of Dynamical Dark Energy Models

Cited by in corpus (9)

• Bouncing Eddington-inspired Born-Infeld cosmologies: an alternative to Inflation ?
• Anthropic versus cosmological solutions to the coincidence problem
• Effective dark energy equation of state in interacting dark energy models
• Quintessence and tachyon dark energy models with a constant equation of state parameter
• Generalized Layzer-Irvine equation: the role of dark energy perturbations in cosmic structure formation
• Chi-square versus median statistics in SNIa data analysis
• Constraints on dark energy evolution
• Assessing the viability of successful reconstruction of the dynamics of dark energy using varying fundamental couplings
• Avoiding unrealistic priors: the case of dark energy constraints from the time variation of the fine-structure constant