University of Sussex
Browse
PhysRevD.99.043518.pdf (493.29 kB)

Optimal constraints on primordial gravitational waves from the lensed CMB

Download (493.29 kB)
Version 2 2023-06-12, 09:00
Version 1 2023-06-09, 16:47
journal contribution
posted on 2023-06-12, 09:00 authored by Julien Carron
We demonstrate how to obtain optimal constraints on a primordial gravitational wave component in lensed Cosmic Microwave Background (CMB) data under ideal conditions. We first derive an estimator of the tensorto-scalar ratio, r, by using an error-controlled close approximation to the exact posterior, under the assumption of Gaussian primordial CMB and lensing deflection potential. This combines fast internal iterative lensing reconstruction with optimal recovery of the unlensed CMB. We evaluate its performance on simulated lownoise polarization data targeted at the recombination peak. We carefully demonstrate our r-posterior estimate is optimal and shows no significant bias, making it the most powerful estimator of primordial gravitational waves from the CMB. We compare these constraints to those obtained from B-mode band-power likelihood analyses on the same simulated data, before and after map-level quadratic estimator delensing, and iterative delensing. Internally, iteratively delensed band powers are only slightly less powerful on average (by less than 10%), promising close-to-optimal constraints from a stage IV CMB experiment.

History

Publication status

  • Published

File Version

  • Published version

Journal

Physical Review D

ISSN

2470-0010

Publisher

American Physical Society

Issue

043518

Volume

99

Page range

1-14

Department affiliated with

  • Physics and Astronomy Publications

Research groups affiliated with

  • Astronomy Centre Publications

Full text available

  • Yes

Peer reviewed?

  • Yes

Legacy Posted Date

2019-02-07

First Open Access (FOA) Date

2019-02-07

First Compliant Deposit (FCD) Date

2019-02-06

Usage metrics

    University of Sussex (Publications)

    Categories

    No categories selected

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC