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Updated: Jul 10, 2026
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Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements
Published on: February 28, 2016
Detection of CMB-Cluster Lensing using Polarization Data from SPTpol.
S Raghunathan1,2, S Patil2, E Baxter3
1Department of Physics and Astronomy, University of California, Los Angeles, California 90095, USA.
Physical Review Letters
|November 26, 2019
Summary
Gravitational lensing from galaxy clusters was detected for the first time using cosmic microwave background (CMB) polarization. This breakthrough enables new cluster cosmology studies with future CMB surveys.
Area of Science:
- Cosmology
- Astrophysics
- Gravitational Lensing
Background:
- Cosmic Microwave Background (CMB) polarization provides a novel probe for cosmological phenomena.
- Galaxy clusters are significant gravitational lenses, influencing the CMB.
- Previous gravitational lensing studies primarily relied on optical or CMB temperature data.
Purpose of the Study:
- To report the first detection of gravitational lensing by galaxy clusters using solely CMB polarization.
- To introduce and validate a new estimator for CMB polarization lensing.
- To establish a foundation for cluster cosmology using CMB polarization in future surveys.
Main Methods:
- Utilized a new estimator analyzing the lensing dipole signature in stacked CMB polarization maps.
- Employed data from the SPTpol 500 deg² survey and the Dark Energy Survey (DES) Year-3 cluster catalog.
- Rotated cluster-centered Stokes QU map cutouts along the local CMB polarization gradient.
Main Results:
- Achieved a statistically significant detection of gravitational lensing at 4.8σ.
- Determined a mean stacked cluster mass of (1.43±0.40)×10¹⁴ M☉.
- Results show strong agreement with optical weak lensing and CMB temperature lensing estimates.
Conclusions:
- This work demonstrates the viability of CMB polarization for detecting galaxy cluster lensing.
- The findings pave the way for future cluster cosmology investigations with next-generation CMB experiments.
- CMB polarization is poised to become a primary channel for cluster lensing measurements in upcoming surveys like CMB-S4.
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