Influence of the correlation prior on reconstruction of the dark energy equation of state

Abstract

Non-parametric reconstruction of the dark energy equation of state (EoS) aims to determine the EoS as a function of redshift without invoking any particular dark energy model, so that the resulting EoS can be free of model-induced biases or artifacts. Without proper regularization, however, such reconstruction is often overwhelmed by the noise of poorly constrained modes. An intuitive regularization scheme is to assume a priori the dark energy EoS to evolve at most slowly with time, which may be enforced by a correlation between the EoS at different epochs. Indeed, studies that impose the correlation prior are able to significantly reduce the uncertainties of the reconstructed EoS and even show hints for dynamical dark energy. In this work, we examine the correlation prior using mock datasets of type Ia supernovae (SNe Ia), baryonic acoustic oscillations (BAOs), age-derived Hubble parameter, Hubble constant, and cosmic microwave background. We find that even though the prior is designed to disfavor evolving equations of state, it can still accommodate spurious oscillating features at high significance. Within the 1000 mock datasets of existing observations that are generated for the concordance cosmological model, i.e., the input dark energy EoS $w=-1$, there are 688 (69) cases recovering an EoS that departs from $-1$ by more than $1\sigma$ ($2\sigma$) in one or more redshift bins. The reconstructed EoS turns up and down markedly in many cases. Moreover, inverting the signs of the randomly assigned errors of the mock data more or less reverses the behavior of the EoS. Spurious results occur even more frequently when idealized SN Ia and BAO data from future surveys are included. Our tests suggest that further studies are needed to ensure accurate reconstruction of the EoS with the correlation prior.

arXiv commentMinor edits to match the accepted version

References in corpus (44)

• Observational Evidence from Supernovae for an Accelerating Universe and a Cosmological Constant
• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Planck 2015 results. XIII. Cosmological parameters
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• The 6dF Galaxy Survey: Baryon Acoustic Oscillations and the Local Hubble Constant
• Dark energy cosmology: the equivalent description via different theoretical models and cosmography tests
• The Cosmic Linear Anisotropy Solving System (CLASS) II: Approximation schemes
• A 2.4% Determination of the Local Value of the Hubble Constant
• Dark Energy and the Accelerating Universe
• Improved cosmological constraints from a joint analysis of the SDSS-II and SNLS supernova samples
• The Clustering of the SDSS DR7 Main Galaxy Sample I: A 4 per cent Distance Measure at z=0.15
• Observational Probes of Cosmic Acceleration
• A 6% measurement of the Hubble parameter at $z\sim 0.45$: direct evidence of the epoch of cosmic re-acceleration
• Baryon Acoustic Oscillations in the Lyα forest of BOSS DR11 quasars
• Dark Energy
• Reconstructing Dark Energy
• Planck 2015 results. XI. CMB power spectra, likelihoods, and robustness of parameters
• CFHTLenS tomographic weak lensing cosmological parameter constraints: Mitigating the impact of intrinsic galaxy alignments
• Dynamical dark energy in light of the latest observations
• The Physics of Cosmic Acceleration
• Uncorrelated Estimates of Dark Energy Evolution
• Parameterization of Dark-Energy Properties: a Principal-Component Approach
• The WiggleZ Dark Energy Survey: Final data release and cosmological results
• DESI and other dark energy experiments in the era of neutrino mass measurements
• Observational Constraints on Dark Energy and Cosmic Curvature
• Planck 2015 results. VIII. High Frequency Instrument data processing: Calibration and maps
• Perturbations of the Quintom Models of Dark Energy and the Effects on Observations
• Nonparametric Dark Energy Reconstruction from Supernova Data
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: tomographic BAO analysis of DR12 combined sample in configuration space
• Examining the evidence for dynamical dark energy
• Evolution of dark energy reconstructed from the latest observations
• Improved Photometric Calibration of the SNLS and the SDSS Supernova Surveys
• Fables of reconstruction: controlling bias in the dark energy equation of state
• Investigating dark energy experiments with principal components
• No Evidence for Dark Energy Dynamics from a Global Analysis of Cosmological Data
• The clustering of galaxies in the completed SDSS-III Baryon Oscillation Spectroscopic Survey: tomographic BAO analysis of DR12 combined sample in Fourier space
• Reconstruction of the Dark Energy equation of state
• Constraining the dark energy equation of state using Bayes theorem and the Kullback-Leibler divergence
• Distance Priors from \emph{Planck} 2015 data
• New Constraints On The Dark Energy Equation of State
• Non-parametric dark energy reconstruction using the tomographic Alcock-Paczynski test
• Estimating the uncorrelated dark energy evolution in the Planck era
• Dark Energy Perturbations Revisited
• Reconstructing the Cosmic Expansion History with a Monotonicity Prior

Cited by in corpus (3)

• Oscillating dark energy in light of the latest observations and its impact on the Hubble tension
• Observational constraints in Delta Gravity: CMB and supernovas
• Hubble tension and matter inhomogeneities: a theoretical perspective