Using H(z) data as a probe of the concordance model

Abstract

Direct observations of the Hubble rate, from cosmic chronometers and the radial baryon acoustic oscillation scale, can out-perform supernovae observations in understanding the expansion history, because supernovae observations need to be differentiated to extract H(z). We use existing H(z) data and smooth the data using a new Gaussian Processes package, GaPP, from which we can also estimate derivatives. The obtained Hubble rate and its derivatives are used to reconstruct the equation of state of dark energy and to perform consistency tests of the LCDM model, some of which are newly devised here. Current data is consistent with the concordance model, but is rather sparse. Future observations will provide a dramatic improvement in our ability to constrain or refute the concordance model of cosmology. We produce simulated data to illustrate how effective H(z) data will be in combination with Gaussian Processes.

9 pages, 8 figures. GaPP available at http://www.acgc.uct.ac.za/~seikel/GAPP/index.html

References in corpus (11)

• Improved Dark Energy Constraints from ~100 New CfA Supernova Type Ia Light Curves
• Reconstructing Dark Energy
• Two new diagnostics of dark energy
• Gaussian Process Cosmography
• Nonparametric Dark Energy Reconstruction from Supernova Data
• Dynamical Dark Energy or Simply Cosmic Curvature?
• A litmus test for Lambda
• Power of Observational Hubble Parameter Data: a Figure of Merit Exploration
• Reconstructing the history of dark energy using maximum entropy
• Non-parametric Dark Energy Degeneracies
• Inference for the dark energy equation of state using Type IA supernova data

Cited by in corpus (10)

• Reconstructing the interaction between dark energy and dark matter using Gaussian Processes
• Breaking of the equivalence principle in the electromagnetic sector and its cosmological signatures
• Measuring the speed of light with Baryon Acoustic Oscillations
• Model-independent Constraints on Cosmic Curvature and Opacity
• Implications from simulated strong gravitational lensing systems: constraining cosmological parameters using Gaussian Processes
• Probing the cosmic opacity from Future Gravitational Wave Standard Sirens
• Exploring the "$L$--$\sigma$" relation of HII galaxies and giant extragalactic HII regions acting as standard candles
• Backreaction and FRW consistency conditions
• Reconstruction of cosmological matter perturbations in Modified Gravity
• Finding Possibility of Dynamical Dark Energy with Hubble Parameters