Cosmological parameter estimation using Very Small Array data out to ℓ = 1500
- Creators
- Rebolo, Rafael
- Battye, Richard A.
- Carreira, Pedro
- Cleary, Kieran
- Davies, Rod D.
- Davis, Richard J.
- Dickinson, Clive
- Génova-Santos, 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
- Pooley, Guy G.
- Rajguru, Nutan
- Rubiño-Martín, José Alberto
- Saunders, Richard D. E.
- Savage, Richard S.
- Scaife, Anna
- Scott, Paul F.
- Slosar, Anže
- Sosa Molina, Pedro
- Taylor, Angela C.
- Titterington, David
- Waldram, Elizabeth
- Watson, Robert A.
- Wilkinson, Althea
Abstract
We estimate cosmological parameters using data obtained by the Very Small Array (VSA) in its extended configuration, in conjunction with a variety of other cosmic microwave background (CMB) data and external priors. Within the flat Λ cold dark matter (ΛCDM) model, we find that the inclusion of high-resolution data from the VSA modifies the limits on the cosmological parameters as compared to those suggested by the Wilkinson Microwave Anisotropy Probe (WMAP) alone, while still remaining compatible with their estimates. We find that Ω_bh²= 0.0234⁺⁰.⁰⁰¹²−₀.₀₀₁₄, Ω_(dm)h²= 0.111⁺⁰.⁰¹⁴−₀.₀₁₆, h= 0.73⁺⁰.⁰⁹−₀.₀₅, n_S= 0.97⁺⁰.⁰⁶−₀.₀₃, 10¹⁰A_S= 23⁺⁷−₃ and τ= 0.14⁺⁰.¹⁴−₀.₀₇ for WMAP and VSA when no external prior is included. On extending the model to include a running spectral index of density fluctuations, we find that the inclusion of VSA data leads to a negative running at a level of more than 95 per cent confidence (n_(run)=−0.069 ± 0.032), something that is not significantly changed by the inclusion of a stringent prior on the Hubble constant. Inclusion of prior information from the 2dF galaxy redshift survey reduces the significance of the result by constraining the value of Ω_m. We discuss the veracity of this result in the context of various systematic effects and also a broken spectral index model. We also constrain the fraction of neutrinos and find that f_ν < 0.087 at 95 per cent confidence, which corresponds to _mν < 0.32 eV when all neutrino masses are equal. Finally, we consider the global best fit within a general cosmological model with 12 parameters and find consistency with other analyses available in the literature. The evidence for n_(run) < 0 is only marginal within this model.
Additional Information
© 2004 RAS, MNRAS. Accepted 2004 June 4. Received 2004 June 4; in original form 2004 February 19. We acknowledge S. Allen for permission to use his XLF probability curves and H. Hoekstra for providing probability curves for CS. The VSA is supported by PPARC and IAC. Partial financial support was provided by the Spanish Ministry of Science and Technology project AYA2001-1657. JAR-M acknowledges the hospitality of the IAC during several visits, and the financial support provided through the European Community's Human Potential Programme under contract HPRN-CT-2002-00124, CMBNET. KL, RS and CD acknowledge support by PPARC studentships. YAH is supported by the Space Research Institute of KACST. AS acknowledges the support of St. Johns College, Cambridge. RAB thanks C. Contaldi and J.Weller for helpful comments and suggestions, and acknowledges the use of the COSMOS supercomputer based at DAMTP, Cambridge. RR thanks the IAC Computer Centre for the intense use of the BEOIAC computer cluster during its commissioning phase.Attached Files
Published - 353-3-747.pdf
Accepted Version - 0402466.pdf
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Additional details
- Eprint ID
- 107694
- Resolver ID
- CaltechAUTHORS:20210122-185027568
- Particle Physics and Astronomy Research Council (PPARC)
- Instituto de Astrofisica de Canarias (IAC)
- AYA2001-1657
- Ministerio de Ciencia e Innovación (MCINN)
- HPRN-CT-2002-00124
- European Union
- Particle Physics and Astronomy Research Council (PPARC)
- King Abdulaziz City for Science and Technology (KACST)
- St. Johns College, Cambridge
- Created
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2021-01-26Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field