Cosmological parameter estimation and Bayesian model comparison using VSA data

Abstract

We constrain the basic comological parameters using the first observations by the Very Small Array (VSA) in its extended configuration, together with existing cosmic microwave background data and other cosmological observations. We estimate cosmological parameters for four different models of increasing complexity. In each case, careful consideration is given to implied priors and the Bayesian evidence is calculated in order to perform model selection. We find that the data are most convincingly explained by a simple flat Lambda-CDM cosmology without tensor modes. In this case, combining just the VSA and COBE data sets yields the 68 per cent confidence intervals Omega_b h^2=0.034 (+0.007, -0.007), Omega_dm h^2 = 0.18 (+0.06, -0.04), h=0.72 (+0.15,-0.13), n_s=1.07 (+0.06,-0.06) and sigma_8=1.17 (+0.25, -0.20). The most general model considered includes spatial curvature, tensor modes, massive neutrinos and a parameterised equation of state for the dark energy. In this case, by combining all recent cosmological data, we find, in particular, 95 percent limit on the tensor-to-scalar ratio R < 0.63 and on the fraction of massive neutrinos f_nu < 0.11; we also obtain the 68 per cent confidence interval w=-1.06 (+0.20, -0.25) on the equation of state of dark energy.

6 pages, 6 figures, version with minor corrections accepted by MNRAS

References in corpus (20)

• Measurements of Omega and Lambda from 42 High-Redshift Supernovae
• Efficient Computation of CMB anisotropies in closed FRW models
• Cosmological parameters from CMB and other data: a Monte-Carlo approach
• Final Results from the Hubble Space Telescope Key Project to Measure the Hubble Constant
• The 2dF Galaxy Redshift Survey: Spectra and redshifts
• MAXIMA-1: A Measurement of the Cosmic Microwave Background Anisotropy on angular scales of 10 arcminutes to 5 degrees
• A measurement by BOOMERANG of multiple peaks in the angular power spectrum of the cosmic microwave background
• DASI First Results: A Measurement of the Cosmic Microwave Background Angular Power Spectrum
• Big-Bang Nucleosynthesis Predictions for Precision Cosmology
• Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra
• Cosmological constraints from the X-ray gas mass fraction in relaxed lensing clusters observed with Chandra
• The Cosmic Microwave Background Anisotropy Power Spectrum measured by Archeops
• Combining cosmological datasets: hyperparameters and Bayesian evidence
• The CMB power spectrum out to l=1400 measured by the VSA
• A Bayesian approach to discrete object detection in astronomical datasets
• First results from the Very Small Array -- III. The CMB power spectrum
• First results from the Very Small Array -- I. Observational methods
• First results from the Very Small Array -- IV. Cosmological parameter estimation
• First results from the Very Small Array -- II. Observations of the CMB
• Zeldovich flow on cosmic vacuum background: new exact nonlinear analytical solution

Cited by in corpus (38)

• MultiNest: an efficient and robust Bayesian inference tool for cosmology and particle physics
• Multimodal nested sampling: an efficient and robust alternative to MCMC methods for astronomical data analysis
• Bayes in the sky: Bayesian inference and model selection in cosmology
• How many cosmological parameters?
• Applications of Bayesian model selection to cosmological parameters
• Cosmic Microwave Weak lensing data as a test for the dark universe
• Isochrone ages for field dwarfs: method and application to the age-metallicity relation
• High sensitivity measurements of the CMB power spectrum with the extended Very Small Array
• Efficient Bayesian inference for multimodal problems in cosmology
• A Bayesian model selection analysis of WMAP3
• The CMB power spectrum out to l=1400 measured by the VSA
• A preference for a non-zero neutrino mass from cosmological data
• Bayesian Selection of sign(mu) within mSUGRA in Global Fits Including WMAP5 Results
• Cosmological parameter estimation using Very Small Array data out to l=1500
• Bayesian model selection and isocurvature perturbations
• A Bayesian analysis of the primordial power spectrum
• Forecasting the Bayes factor of a future observation
• Post-WMAP Assessment of Infrared Cutoff in the Primordial Spectrum from Inflation
• Markov chain Monte Carlo analysis of Bianchi VII_h models
• Analytic Methods for Cosmological Likelihoods
• Bayesian joint analysis of cluster weak lensing and Sunyaev-Zel'dovich effect data
• Galaxy Zoo: Chiral correlation function of galaxy spins
• WMAP 3-year primordial power spectrum
• Very Small Array observations of the Sunyaev-Zel'dovich effect in nearby galaxy clusters
• Model selection forecasts for the spectral index from the Planck satellite
• Did Boomerang hit MOND?
• Bayesian Model Averaging in Astrophysics: A Review
• Estimating the bispectrum of the Very Small Array data
• Galactic Foreground Constraints from the Python V Cosmic Microwave Background Anisotropy Data
• Keck spectroscopy of CLASS gravitational lenses
• Application of Bayesian model averaging to measurements of the primordial power spectrum
• Constraining Light Gravitino Mass from Cosmic Microwave Background
• Non-Gaussianity in the Very Small Array CMB maps with Smooth-Goodness-of-fit tests
• Searching for non-Gaussianity in the VSA data
• Probing the primordial power spectra with inflationary priors
• CMB observations from the CBI and VSA: A comparison of coincident maps and parameter estimation methods
• Observing the CMB at High-l using the VSA and AMI
• A Chi-Squared Analysis of the Measurements of Two Cosmological Parameters Over Time