English

Revised cosmological parameters after BICEP 2 and BOSS

Cosmology and Nongalactic Astrophysics 2015-02-13 v2 General Relativity and Quantum Cosmology

Abstract

Estimation of parameters of the \lq standard\rq \,model of cosmology have dramatically improved over past few decades due to increasingly exquisite measurements made by Cosmic Microwave Background (CMB) experiments. Recent data from Planck matches well with the minimal Λ\LambdaCDM model. A likelihood analysis using Planck, WMAP and a selection of high resolution experiments (highL), tensor to scalar ratio r0.002r_{0.002} is found to be <0.11<0.11 when dns/dlnk=0dn_{s}/d\ln k = 0. Planck also imposes an upper bound on neutrino mass mν<0.23\sum m_\nu<0.23\,eV using Planck+WMAP+highL+BAO likelihood. However, recently results from BICEP 2 claims the detection of r=0.20.05+0.07r= 0.2^{+0.07}_{-0.05} from polarization spectra. Further, results from SDSS-III BOSS large scale galaxy survey constrains the total neutrino mass to mν=0.36±0.10\sum m_\nu=0.36 \pm 0.10 eV. It is important to study the consequences of these new measurements on other cosmological parameters. In this paper we assess the revised constraints on cosmological parameters in light of these two measurements that are in some tension with the constraints from Planck. Using the prior on mν\sum m_\nu as measured by SDSS-III BOSS and BICEP 2 likelihood, we find that the model with running spectral index (dns/dlnk0dn_{s}/d\ln k \neq 0) leads to a value of AL>1A_L>1 at 3.1σ3.1 \sigma. But, the model with dns/dlnk=0dn_{s}/d\ln k =0 makes ALA_L consistent with 11, at 2.1σ2.1\sigma and also shows that NeffN_{\rm eff} is consistent with its theoretical value of 3.0463.046 at around 2σ2\sigma. Therefore, the analysis in this paper shows that the model with dns/dlnk=0dn_{s}/d\ln k =0 gives consistency with other cosmological parameters (NeffN_{\rm eff} and ALA_L ) when the current limits on mν\sum m_\nu and r0.05r_{0.05} are considered. However, on reducing the value of r0.05r_{0.05}, the model with non-zero dns/dlnkdn_{s}/d\ln k gives consistent result of AL=1A_L =1 [abridged].

Keywords

Cite

@article{arxiv.1406.0857,
  title  = {Revised cosmological parameters after BICEP 2 and BOSS},
  author = {Santanu Das and Suvodip Mukherjee and Tarun Souradeep},
  journal= {arXiv preprint arXiv:1406.0857},
  year   = {2015}
}

Comments

14 pages, 10 figures. Matches the published version

R2 v1 2026-06-22T04:29:52.940Z