Skip to main content
SpringerLink
Log in

Cosmological parameter fittings with the BICEP2 data

  • Article
  • Special Topic: BICEP2 and Beyond
  • Published:
Science China Physics, Mechanics & Astronomy Aims and scope Submit manuscript

Abstract

Combining the latest Planck, Wilkinson Microwave Anisotropy Probe (WMAP), and baryon acoustic oscillation (BAO) data, we exploit the recent cosmic microwave background (CMB) B-mode power spectra data released by the BICEP2 collaboration to constrain the cosmological parameters of the LCDM model, especially the primordial power spectra parameters of the scalar and the tensor modes, n s , α s , r, n t . We obtain constraints on the parameters for a lensed LCDM model using the Markov Chain Monte Carlo (MCMC) technique, the marginalized 68% bounds are r = 0.1043 +0.0307−0.0914 , n s = 0.9617 +0.0061−0.0061 , α s = −0.0175 +0.0105−0.0097 , n t = 0.5198 +0.4515−0.4579 .We find that a blue tilt for n t is favored slightly, but it is still well consistent with flat or even red tilt. Our r value is slightly smaller than the one obtained by the BICEP group, in that we permit n t as a free parameter without imposing the single-field slow roll inflation consistency relation. When we impose this relation, then r = 0.2130 +0.0446−0.0609 . For most other parameters, the best fit values and measurement errors are not altered significantly by the introduction of the BICEP2 data.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. BICEP2 Collaboration, Ade P, et al. BICEP2 I: Detection of B-mode polarization at degree angular scales. arXiv:1403.3985 [astro-ph.CO]

  2. BICEP2 Collaboration, Ade P A R, et al. BICEP2 II: Experiment and three-year data set. arXiv:1403.4302 [astro-ph.CO]

  3. Hertzberg M P. Inflation, symmetry, and B-modes. arXiv:1403.5253 [hep-th]

  4. Choudhury S, Mazumdar A. Reconstructing inflationary potential from BICEP2 and running of tensor modes. arXiv:1403.5549 [hep-th]

  5. Ma Y Z, Wang Y. Reconstructing the local potential of inflation with BICEP2 data. arXiv:1403.4585 [astro-ph.CO]

  6. Gong Y. The challenge for single field inflation with BICEP2 result. arXiv:1403.5716 [gr-qc]

  7. Xia J Q, Cai Y F, Li H, et al. Evidence for bouncing evolution before inflation after BICEP2. arXiv:1403.7623 [astro-ph.CO]

  8. Cai Y F, Gong J O, Pi S. Conformal description of inflation and primordial B-modes. arXiv:1404.2560 [hep-th]

  9. Zhao W, Cheng C, Huang Q G. Hint of relic gravitational waves in the Planck and WMAP data. arXiv:1403.3919 [astro-ph.CO]

  10. Zhao W, Grishchuk L. Relic gravitational waves: latest revisions and preparations for new data. Phys Rev D, 2010, 82: 123008

    Article  ADS  Google Scholar 

  11. Zhang J F, Li Y H, Zhang X. Sterile neutrinos help reconcile the observational results of primordial gravitational waves from Planck and BICEP2. arXiv:1403.7028 [astro-ph.CO]

  12. Planck Collaboration, Ade P, et al. Planck 2013 results. XVI. Cosmological parameters. arXiv:1303.5076 [astro-ph.CO]

  13. Hinshaw G, Larson D, Komatsu E, et al. Nine-year wilkinson microwave anisotropy probe (WMAP) observations: cosmological parameter results. Astrophys J Suppl Ser, 2013, 208(2): 19

    Article  ADS  Google Scholar 

  14. Bennett C L, Larson D, Weiland J L, et al. Nine-year wilkinson microwave anisotropy probe (WMAP) observations: final maps and results. Astrophys J Suppl Ser, 2013, 208(2): 20

    Article  ADS  Google Scholar 

  15. Anderson L, Aubourg E, Bailey S, et al. The clustering of galaxies in the SDSS-III baryon oscillation spectroscopic survey: Baryon acoustic oscillations in the Data Release 9 spectroscopic galaxy sample. Mon Not R Astron Soc, 2013, 427(4): 3435–3467

    Article  ADS  Google Scholar 

  16. Padmanabhan N, Xu X, Eisenstein D J, et al. A 2 percent distance to z= 0.35 by reconstructing baryon acoustic oscillations—I. Methods and application to the Sloan Digital Sky Survey. Mon Not R Astron Soc, 2012, 427(3): 2132–2145

    Article  ADS  Google Scholar 

  17. Beutler F, Blake C, Colless M, et al. The 6dF Galaxy Survey: baryon acoustic oscillations and the local Hubble constant. Mon Not R Astron Soc, 2011, 416(4): 3017–3032

    Article  ADS  Google Scholar 

  18. Lewis A, Bridle S. Cosmological parameters from cmb and other data: a monte-carlo approach. Phys Rev, 2002: 103511

  19. Abazajian K N, Aslanyan G, Easther R, et al. The Knotted Sky II: Does BICEP2 require a nontrivial primordial power spectrum? arXiv: 1403.5922 [astro-ph.CO]

  20. Gong J O. Non-trivial running of the primordial tensor spectrum. arXiv:1403.5163 [astro-ph.CO]

  21. Brandenberger R H, Nayeri A, Patil S P. Closed string thermodynamics and a blue tensor spectrum. arXiv:1403.4927 [astro-ph.CO]

  22. Gerbino M, Marchini A, Pagano L, et al. Blue gravity waves from BICEP2? arXiv:1403.5732 [astro-ph.CO]

  23. Kosowsky A. Turner M S. Cbr anisotropy and the running of the scalar spectral index. Phys Rev D, 1995, 52: 1739. arXiv:astro-ph/9504071

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. National Astronomical Observatories, Chinese Academy of Sciences, Beijing, 100012, China

    FengQuan Wu, YiChao Li, YouJun Lu & XueLei Chen

  2. University of Chinese Academy of Sciences, Beijing, 100049, China

    YiChao Li

  3. Center of High Energy Physics, Peking University, Beijing, 100871, China

    XueLei Chen

Authors
  1. FengQuan Wu
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. YiChao Li
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. YouJun Lu
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. XueLei Chen
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to XueLei Chen.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Wu, F., Li, Y., Lu, Y. et al. Cosmological parameter fittings with the BICEP2 data. Sci. China Phys. Mech. Astron. 57, 1449–1454 (2014). https://doi.org/10.1007/s11433-014-5516-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11433-014-5516-z

Keywords

Search

Navigation