# Revised cosmological parameters after BICEP 2 and BOSS

## Abstract

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 r{sub 0.002} is found to be <0.11 when dn{sub s}/dln k = 0. Planck also imposes an upper bound on neutrino mass ∑ m{sub ν}<0.23 eV using Planck + WMAP + highL + BAO likelihood. However, recently results from BICEP 2 claims the detection of r= 0.2{sup +0.07}{sub −0.05} from polarization spectra. Further, results from SDSS-III BOSS large scale galaxy survey constrains the total neutrino mass to ∑ m{sub ν}=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 A{sub L} > 1 at 2σ hints at a potentially important internal inconsistency. Therefore,more »

- Authors:

- Inter-University Centre for Astronomy and Astrophysics, Post Bag 4, Ganeshkhind, Pune 411007 (India)

- Publication Date:

- OSTI Identifier:
- 22381989

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Journal of Cosmology and Astroparticle Physics; Journal Volume: 2015; Journal Issue: 02; Other Information: Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; COSMOLOGY; EV RANGE; GALAXIES; GRAVITATIONAL LENSES; LIMITING VALUES; NEUTRINOS; POLARIZATION; RELICT RADIATION; SENSITIVITY; SPECTRA

### Citation Formats

```
Das, Santanu, Mukherjee, Suvodip, and Souradeep, Tarun, E-mail: santanud@iucaa.ernet.in, E-mail: suvodip@iucaa.ernet.in, E-mail: tarun@iucaa.ernet.in.
```*Revised cosmological parameters after BICEP 2 and BOSS*. United States: N. p., 2015.
Web. doi:10.1088/1475-7516/2015/02/016.

```
Das, Santanu, Mukherjee, Suvodip, & Souradeep, Tarun, E-mail: santanud@iucaa.ernet.in, E-mail: suvodip@iucaa.ernet.in, E-mail: tarun@iucaa.ernet.in.
```*Revised cosmological parameters after BICEP 2 and BOSS*. United States. doi:10.1088/1475-7516/2015/02/016.

```
Das, Santanu, Mukherjee, Suvodip, and Souradeep, Tarun, E-mail: santanud@iucaa.ernet.in, E-mail: suvodip@iucaa.ernet.in, E-mail: tarun@iucaa.ernet.in. Sun .
"Revised cosmological parameters after BICEP 2 and BOSS". United States.
doi:10.1088/1475-7516/2015/02/016.
```

```
@article{osti_22381989,
```

title = {Revised cosmological parameters after BICEP 2 and BOSS},

author = {Das, Santanu and Mukherjee, Suvodip and Souradeep, Tarun, E-mail: santanud@iucaa.ernet.in, E-mail: suvodip@iucaa.ernet.in, E-mail: tarun@iucaa.ernet.in},

abstractNote = {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 r{sub 0.002} is found to be <0.11 when dn{sub s}/dln k = 0. Planck also imposes an upper bound on neutrino mass ∑ m{sub ν}<0.23 eV using Planck + WMAP + highL + BAO likelihood. However, recently results from BICEP 2 claims the detection of r= 0.2{sup +0.07}{sub −0.05} from polarization spectra. Further, results from SDSS-III BOSS large scale galaxy survey constrains the total neutrino mass to ∑ m{sub ν}=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 A{sub L} > 1 at 2σ hints at a potentially important internal inconsistency. Therefore, we also include a study of the constraints on A{sub L}. Using the prior on ∑ m{sub ν} as measured by SDSS-III BOSS and BICEP 2 likelihood, we find that the model with running spectral index (dn{sub s}/dln k ≠ 0) leads to a value of A{sub L}>1 at 3.1 σ. But, the model with dn{sub s}/dln k =0 makes A{sub L} consistent with 1, at 2.1σ and also shows that N{sub eff} is consistent with its theoretical value of 3.046 at around 2σ. Therefore, the analysis in this paper shows that the model with dn{sub s}/dln k =0 gives consistency with other cosmological parameters (N{sub eff} and A{sub L} ) when the current limits on ∑ m{sub ν} and r{sub 0.05} are considered. However, on reducing the value of r{sub 0.05}, the model with non-zero dn{sub s}/dln k gives consistent result of A{sub L} =1.},

doi = {10.1088/1475-7516/2015/02/016},

journal = {Journal of Cosmology and Astroparticle Physics},

number = 02,

volume = 2015,

place = {United States},

year = {Sun Feb 01 00:00:00 EST 2015},

month = {Sun Feb 01 00:00:00 EST 2015}

}