Open AccessCosmological parameter estimation and Bayesian model comparison using Very Small Array data
Author(s) -
Slosar Anže,
Carreira Pedro,
Cleary Kieran,
Davies Rod D.,
Davis Richard J.,
Dickinson Clive,
GenovaSantos Ricardo,
Grainge Keith,
Gutiérrez Carlos M.,
Hafez Yaser A.,
Hobson Michael P.,
Jones Michael E.,
Kneissl Rüdiger,
Lancaster Katy,
Lasenby Anthony,
Leahy J. P.,
Maisinger Klaus,
Marshall Phil J.,
Pooley Guy G.,
Rebolo Rafael,
RubiñoMartin José Alberto,
Rusholme Ben,
Saunders Richard D. E.,
Savage Richard,
Scott Paul F.,
Sosa Molina Pedro J.,
Taylor Angela C.,
Titterington David,
Waldram Elizabeth,
Watson Robert A.,
Wilkinson Althea
Publication year - 2003
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1046/j.1365-8711.2003.06564.x
Subject(s) - physics , cosmic microwave background , dark energy , neutrino , cosmology , equation of state , cosmic background radiation , tensor (intrinsic definition) , prior probability , lambda cdm model , bayesian probability , astrophysics , statistical physics , theoretical physics , particle physics , statistics , quantum mechanics , geometry , anisotropy , mathematics
We constrain the basic cosmological 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 ΛCDM cosmology without tensor modes. In this case, combining just the VSA and COBE data sets yields the 68 per cent confidence intervals Ω b h 2 = 0.034 + 0.007 − 0.007, Ω dm h 2 = 0.18 + 0.06 − 0.04, h = 0.72 + 0.15 − 0.13, n s = 1.07 + 0.06 − 0.06and σ 8 = 1.17 + 0.25 − 0.20. The most general model considered includes spatial curvature, tensor modes, massive neutrinos and a parametrized equation of state for the dark energy. In this case, by combining all recent cosmological data, we find, in particular, a 95 per cent limit on the tensor‐to‐scalar ratio R < 0.63 and on the fraction of massive neutrinos f ν < 0.11 ; we also obtain the 68 per cent confidence interval w =−1.06 + 0.20 − 0.25on the equation of state of dark energy.