Reconstruction of the Dark Energy equation of state

Abstract

One of the main challenges of modern cosmology is to investigate the nature of dark energy in our Universe. The properties of such a component are normally summarised as a perfect fluid with a (potentially) time-dependent equation-of-state parameter $w(z)$. We investigate the evolution of this parameter with redshift by performing a Bayesian analysis of current cosmological observations. We model the temporal evolution as piecewise linear in redshift between `nodes', whose $w$-values and redshifts are allowed to vary. The optimal number of nodes is chosen by the Bayesian evidence. In this way, we can both determine the complexity supported by current data and locate any features present in $w(z)$. We compare this node-based reconstruction with some previously well-studied parameterisations: the Chevallier-Polarski-Linder (CPL), the Jassal-Bagla-Padmanabhan (JBP) and the Felice-Nesseris-Tsujikawa (FNT). By comparing the Bayesian evidence for all of these models we find an indication towards possible time-dependence in the dark energy equation-of-state. It is also worth noting that the CPL and JBP models are strongly disfavoured, whilst the FNT is just significantly disfavoured, when compared to a simple cosmological constant $w=-1$. We find that our node-based reconstruction model is slightly disfavoured with respect to the $\Lambda$CDM model.

17 pages, 5 figures, minor corrections

References in corpus (25)

• Models of f(R) Cosmic Acceleration that Evade Solar-System Tests
• Spectra and Light Curves of Six Type Ia Supernovae at 0.511 < z < 1.12 and the Union2 Compilation
• Disappearing cosmological constant in f(R) gravity
• Bayes in the sky: Bayesian inference and model selection in cosmology
• Modified f(R) gravity consistent with realistic cosmology: from matter dominated epoch to dark energy universe
• Reconstructing Dark Energy
• Two new diagnostics of dark energy
• Imperfect Dark Energy from Kinetic Gravity Braiding
• Can dark energy evolve to the Phantom?
• WMAP constraints on low redshift evolution of dark energy
• Gaussian Process Cosmography
• Consequences of dark matter-dark energy interaction on cosmological parameters derived from SNIa data
• Crossing the Phantom Divide with Parameterized Post-Friedmann Dark Energy
• Nonparametric Dark Energy Reconstruction from Supernova Data
• Nonparametric Reconstruction of the Dark Energy Equation of State
• Crossing the phantom divide without phantom matter
• Model selection applied to reconstruction of the Primordial Power Spectrum
• Bayesian Calibrated Significance Levels Applied to the Spectral Tilt and Hemispherical Asymmetry
• Non-minimal quintessence and phantom with nearly flat potentials
• Crossing Statistic: Reconstructing the Expansion History of the Universe
• f(R) Gravity and its Cosmological Implications
• Reconstructing the history of dark energy using maximum entropy
• High-resolution temporal constraints on the dynamics of dark energy
• Non-parametric Dark Energy Degeneracies
• Current cosmological constraints on the curvature, dark energy and modified gravity

Cited by in corpus (28)

• The CosmoVerse White Paper: Addressing observational tensions in cosmology with systematics and fundamental physics
• Precision cosmology with Padé rational approximations: theoretical predictions versus observational limits
• Model-independent reconstruction of the Interacting Dark Energy Kernel: Binned and Gaussian process
• Parametric and nonparametric methods hint dark energy evolution
• Simple-graduated dark energy and spatial curvature
• Constraining the dark energy equation of state using Bayes theorem and the Kullback-Leibler divergence
• Reconstruction of the neutrino mass as a function of redshift
• Dynamical dark energy in the light of DESI 2024 data
• Neural network reconstructions for the Hubble parameter, growth rate and distance modulus
• Narrowing down the possible explanations of cosmic acceleration with geometric probes
• A divergence-free parametrization for dynamical dark energy
• Reconstructing dark energy with model independent methods after DESI DR2 BAO
• Coupled Multi Scalar Field Dark Energy
• Neural Networks Optimized by Genetic Algorithms in Cosmology
• Non-parametric reconstruction of cosmological observables using Gaussian Processes Regression
• Late Time Acceleration of the 3-Space in a Higher Dimensional Steady State Universe in Dilaton Gravity
• Interacting Scalar fields: Dark matter and early dark energy
• Do we need wavelets in the late Universe?
• A possible late-time transition of $M_B$ inferred via neural networks
• FlexKnot as a Generalised Model of the Sky-averaged 21-cm Signal at z ~ 6-30 in the Presence of Systematics
• A comprehensive data-driven odyssey to explore the equation of state of dark energy
• Bayesian deep learning for dark energy
• Knot reconstruction of the scalar primordial power spectrum with Planck, ACT, and SPT CMB data
• Holographic energy density on Hořava-Lifshitz cosmology
• Performance of Non-Parametric Reconstruction Techniques in the Late-Time Universe
• Exploring the Evolution of Nonlinear Electrodynamics in the Universe: A Dynamical Systems Approach
• Observational Constraints and Geometric Diagnostics of Barboza-Alcaniz and Logarithmic Dark Energy Parametrizations
• How Holographic is the Dark Energy? A Spline Nodal reconstruction approach