Revised cosmological parameters after BICEP 2 and BOSS

Das, Santanu ; Mukherjee, Suvodip ; Souradeep, Tarun (2015) Revised cosmological parameters after BICEP 2 and BOSS Journal of Cosmology and Astroparticle Physics, 2015 (02). No pp. given. ISSN 1475-7516

Full text not available from this repository.

Official URL:

Related URL:


Estimation of parameters of the 'standard' 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 ΛCDM model. A likelihood analysis using Planck, WMAP and a selection of high resolution experiments (highL), tensor to scalar ratio r0.002 is found to be < 0.11 when dns/d ln k = 0. Planck also imposes an upper bound on neutrino mass ∑ mν< 0.23 eV using Planck + WMAP + highL + BAO likelihood. However, recently results from BICEP 2 claims the detection of r= 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 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. The sensitivity of Planck to weak lensing effect on the CMB angular power spectrum suggests that the normalized amplitude of physical lensing power AL > 1 at 2σ hints at a potentially important internal inconsistency. Therefore, we also include a study of the constraints on AL. Using the prior on ∑ mν as measured by SDSS-III BOSS and BICEP 2 likelihood, we find that the model with running spectral index (dns/d ln k ≠ 0) leads to a value of AL>1 at 3.1 σ. But, the model with dns/d ln k =0 makes AL consistent with 1, at 2.1σ and also shows that Neff is consistent with its theoretical value of 3.046 at around 2σ. Therefore, the analysis in this paper shows that the model with dns/d ln k =0 gives consistency with other cosmological parameters (Neff and AL ) when the current limits on ∑ mv and r0.05 are considered. However, on reducing the value of r0.05, the model with non-zero dns/d ln k gives consistent result of AL =1.

Item Type:Article
Source:Copyright of this article belongs to Institute of Physics.
ID Code:107558
Deposited On:26 Dec 2017 07:05
Last Modified:26 Dec 2017 07:05

Repository Staff Only: item control page