Structure of the Polarization Field Around High Peaks of the CMB Anisotropy

1997 ◽  
Vol 06 (05) ◽  
pp. 515-533 ◽  
Author(s):  
P. Arbuzov ◽  
E. Kotok ◽  
P. Naselsky ◽  
I. Novikov
Keyword(s):  
Cosmic Microwave Background ◽  
Cross Correlation ◽  
Local Maximum ◽  
Polarization Field ◽  
Specific Structure ◽  
Microwave Background ◽  
Specific Shape ◽  
The Cross

We present computations of the statistics of the polarization field around high peaks of the cosmis microwave background anisotropy. We studied the correlated and uncorrelated with the anisotropy parts of polarization in the vicinity of isolated peaks of anisotropy in order to demonstrate how these peaks determine the structure of the polarization fields. We have shown that the level of cross-correlation between anisotropy and polarization increases in ν times around ν-heigh isolated peaks of anisotropy. Such a peak forms the specific shape of polarization around itself. The polarization of the cosmic microwave background correlated with 3σ-peaks of anisotropy is formed mainly between the cross-levels 1.5σ and 2.5σ. This polarization has a local maximum ~30÷45% around 3σ-peaks and looks like "rings" around the peaks. This specific structure of the polarization field would be effective for further investigation of the primordial signal and noise in the maps of anisotropy and polarization of the cosmic microwave background.

scholarly journals Detection of a Cross-correlation between Cosmic Microwave Background Lensing and Low-density Points

2021 ◽  
Vol 923 (2) ◽  
pp. 153
Author(s):  
Fuyu Dong ◽  
Pengjie Zhang ◽  
Le Zhang ◽  
Ji Yao ◽  
Zeyang Sun ◽  
...  
Keyword(s):  
Cosmic Microwave Background ◽  
Gravitational Lensing ◽  
Large Scale ◽  
Cross Correlation ◽  
Absolute Magnitude ◽  
Low Density ◽  
Microwave Background ◽  
Large Scale Structures ◽  
The Universe ◽  
Good Agreement

Abstract Low-density points (LDPs), obtained by removing high-density regions of observed galaxies, can trace the large-scale structures (LSSs) of the universe. In particular, it offers an intriguing opportunity to detect weak gravitational lensing from low-density regions. In this work, we investigate the tomographic cross-correlation between Planck cosmic microwave background (CMB) lensing maps and LDP-traced LSSs, where LDPs are constructed from the DR8 data release of the DESI legacy imaging survey, with about 106–107 galaxies. We find that, due to the large sky coverage (20,000 deg2) and large redshift depth (z ≤ 1.2), a significant detection (10σ–30σ) of the CMB lensing–LDP cross-correlation in all six redshift bins can be achieved, with a total significance of ∼53σ over ℓ ≤ 1024. Moreover, the measurements are in good agreement with a theoretical template constructed from our numerical simulation in the WMAP 9 yr ΛCDM cosmology. A scaling factor for the lensing amplitude A lens is constrained to A lens = 1 ± 0.12 for z < 0.2, A lens = 1.07 ± 0.07 for 0.2 < z < 0.4, and A lens = 1.07 ± 0.05 for 0.4 < z < 0.6, with the r-band absolute magnitude cut of −21.5 for LDP selection. A variety of tests have been performed to check the detection reliability against variations in LDP samples and galaxy magnitude cuts, masks, CMB lensing maps, multipole ℓ cuts, sky regions, and photo-z bias. We also perform a cross-correlation measurement between CMB lensing and galaxy number density, which is consistent with the CMB lensing–LDP cross-correlation. This work therefore further convincingly demonstrates that LDP is a competitive tracer of LSS.

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