Delensing Cosmic Microwave Background B-modes with the Square Kilometre Array Radio Continuum Survey

Abstract

We explore the potential use of the Radio Continuum (RC) survey conducted by the Square Kilometre Array (SKA) to remove (delens) the lensing-induced B-mode polarization and thus enhance future cosmic microwave background (CMB) searches for inflationary gravitational waves. Measurements of large-scale B-modes of the CMB are considered to be the best method for probing gravitational waves from the cosmic inflation. Future CMB experiments will, however, suffer from contamination by non-primordial B-modes, one source of which is the lensing B-modes. Delensing, therefore, will be required for further improvement of the detection sensitivity for gravitational waves. Analyzing the use of the two-dimensional map of galaxy distribution provided by the SKA RC survey as a lensing mass tracer, we find that joint delensing using near future CMB experiments and the SKA phase 1 will improve the constraints on the tensor-to-scalar ratio by more than a factor of $\sim 2$ compared to those without the delensing analysis. Compared to the use of CMB data alone, the inclusion of the SKA phase 1 data will increase the significance of the constraints on the tensor-to-scalar ratio by a factor $1.2$-$1.6$. For LiteBIRD combined with a ground-based experiment such as Simons Array and Advanced ACT, the constraint on the tensor-to-scalar ratio when adding SKA phase 2 data is improved by a factor of $2.3$-$2.7$, whereas delensing with CMB data alone improves the constraints by only a factor $1.3$-$1.7$. We conclude that the use of SKA data is a promising method for delensing upcoming CMB experiments such as LiteBIRD.

10 pages, 6 figures, references added, accepted for publication in PRD

References in corpus (8)

• NuSTAR and Suzaku observations of the hard state in Cygnus X-1: locating the inner accretion disk
• Delensing the CMB with the Cosmic Infrared Background
• Precision Epoch of Reionization studies with next-generation CMB experiments
• Cosmic 21-cm Delensing of Microwave Background Polarization and the Minimum Detectable Energy Scale of Inflation
• Magnification-Temperature Correlation: the Dark Side of ISW Measurements
• Detectability of CMB tensor B modes via delensing with weak lensing galaxy surveys
• Lensing reconstruction from a patchwork of polarization maps
• Non-Gaussian Structure of B-mode Polarization after Delensing

Cited by in corpus (26)

• General Relativity and Cosmology: Unsolved Questions and Future Directions
• BICEP2 / Keck Array VIII: Measurement of gravitational lensing from large-scale B-mode polarization
• Demonstration of cosmic microwave background delensing using the cosmic infrared background
• Testing statistics of the CMB B-mode polarization toward unambiguously establishing quantum fluctuation of vacuum
• The Simons Observatory: Constraining inflationary gravitational waves with multi-tracer B-mode delensing
• Future cosmic microwave background delensing with galaxy surveys
• Cross-correlating radio continuum surveys and CMB lensing: constraining redshift distributions, galaxy bias and cosmology
• Limitations of CMB B-mode template delensing
• Comparison of delensing methodologies and assessment of the delensing capabilities of future experiments
• Dark neutrino interactions make gravitational waves blue
• LiteBIRD Science Goals and Forecasts: Improving Sensitivity to Inflationary Gravitational Waves with Multitracer Delensing
• Principal component analysis of the primordial tensor power spectrum
• A numerical study of observational systematic errors in lensing analysis of CMB polarization
• The B-mode polarization of CMB and Cosmic Neutrino Background
• Delensing Degree-Scale $B$-Mode Polarization with High-Redshift Line Intensity Mapping
• Cosmology with the Square Kilometre Array by SKA-Japan
• Cosmology from LOFAR Two-metre Sky Survey Data Release 2: Cross-correlation with the cosmic microwave background
• Delensing of Cosmic Microwave Background Polarization with machine learning
• Impact of nonlinear growth of the large-scale structure on CMB B-mode delensing
• Unified approach to secondary effects on the CMB B-mode polarization
• Joint Bayesian estimation of tensor and lensing B-modes in the power spectrum of CMB polarization data
• Characterization of Extragalactic Point-Sources on E- and B-mode Maps of the CMB Polarization
• Delensing CMB B-modes using galaxy surveys: the effect of galaxy bias and matter clustering non-linearities
• Cross-correlating the EMU Pilot Survey 1 with CMB lensing: Constraints on cosmology and galaxy bias with harmonic-space power spectra
• LiteBIRD science goals and forecasts: improved full-sky reconstruction of the gravitational lensing potential through the combination of Planck and LiteBIRD data
• Systematic effects on lensing reconstruction from a patchwork of CMB polarization maps