Parameterizing and Measuring Dark Energy Trajectories from Late-Inflatons

Abstract

Bulk dark energy properties are determined by the redshift evolution of its pressure-to-density ratio, $w_{de}(z)$. An experimental goal is to decide if the dark energy is dynamical, as in the quintessence (and phantom) models treated here. We show that a three-parameter approximation $w_{de}(z;{\epsilon }_s,{\epsilon }_{\varphi \infty },{\zeta }_s)$ fits well the ensemble of trajectories for a wide class of late-inflaton potentials $V(\varphi )$. Markov Chain Monte Carlo probability calculations are used to confront our $w_{de}(z)$ trajectories with current observational information on Type Ia supernova, Cosmic Microwave Background, galaxy power spectra, weak lensing and the Lyman-$\alpha$ forest. We find the best constrained parameter is a low redshift slope parameter, ${\epsilon }_s\propto (\partial \ln V/\partial \varphi {)}^2$ when the dark energy and matter have equal energy densities. A tracking parameter ${\epsilon }_{\varphi \infty }$ defining the high-redshift attractor of $1+w_{de}$ is marginally constrained. Poorly determined is ${\zeta }_s$, characterizing the evolution of ${\epsilon }_s$, and a measure of ${\partial }^2\ln V/\partial {\varphi }^2$ . The constraints we find already rule out some popular quintessence and phantom models, or restrict their potential parameters. We also forecast how the next generation of cosmological observations improve the constraints: by a factor of about five on ${\epsilon }_s$ and ${\epsilon }_{\varphi \infty }$, but with ${\zeta }_s$ remaining unconstrained (unless the true model significantly deviates from $\Lambda$CDM). Thus potential reconstruction beyond an overall height and a gradient is not feasible for the large space of late-inflaton models considered here.

References in corpus (26)

• Dynamics of dark energy
• New Hubble Space Telescope Discoveries of Type Ia Supernovae at z > 1: Narrowing Constraints on the Early Behavior of Dark Energy
• Observational Constraints on the Nature of the Dark Energy: First Cosmological Results from the ESSENCE Supernova Survey
• Approaches to Understanding Cosmic Acceleration
• Baryon Acoustic Oscillation Intensity Mapping as a Test of Dark Energy
• High resolution CMB power spectrum from the complete ACBAR data set
• CMBPol Mission Concept Study: Probing Inflation with CMB Polarization
• A kinematical approach to dark energy studies
• COSMOS: 3D weak lensing and the growth of structure
• A f(R) gravity without cosmological constant
• Thawing quintessence with a nearly flat potential
• Polarization Observations with the Cosmic Background Imager
• The Dynamics of Quintessence, The Quintessence of Dynamics
• Kinetic k-essence and Quintessence
• Mapping the Cosmological Expansion
• Present and future evidence for evolving dark energy
• Dynamical behavior of generic quintessence potentials: constraints on key dark energy observables
• Tracking quintessence by cosmic shear - Constraints from VIRMOS-Descart and CFHTLS and future prospects
• Calibrating Dark Energy
• A combined analysis of 3D Weak Lensing, Lyman-alpha forest and WMAP year three data
• Measuring deviations from a cosmological constant: a field-space parameterization
• Measuring Dark Energy with Gamma-Ray Bursts and Other Cosmological Probes
• Evolution of Oscillating Scalar Fields as Dark Energy
• Narrowing Constraints with Type Ia Supernovae: Converging on a Cosmological Constant
• Power Spectra to 1% Accuracy between Dynamical Dark Energy Cosmologies
• Cosmological Parameters from the QUaD CMB polarization experiment

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