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The Lensing Template Left Half the B-Mode Power Behind

SPT-3G and Planck data produced a foreground-robust template intended to clear contamination from primordial-wave searches.

Published Updated Story ID: mp-2026-08-08-011
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Summary

SPT-3G and Planck data produced a foreground-robust template intended to clear contamination from primordial-wave searches.

The team combined SPT-3G polarization and reconstructed lensing data with a Planck cosmic-infrared-background tracer, then tested estimators with different foreground immunity. Simulations put residual foreground bias below 10 percent of the template power spectrum's statistical uncertainty for the profile-hardened construction; data-difference tests found no significant contamination. Its residual lensing B-mode power averaged about 0.48 over the stated angular range, which the authors call the highest delensing efficiency for such a template to date; it has not detected primordial gravitational waves.

Why it matters

SPT-3G and Planck data produced a foreground-robust template intended to clear contamination from primordial-wave searches.

Limits and context

  • Its residual lensing B-mode power averaged about 0.48 over the stated angular range, which the authors call the highest delensing efficiency for such a template to date; it has not detected primordial gravitational waves.

Key claims

  1. SPT-3G and Planck data produced a foreground-robust template intended to clear contamination from primordial-wave searches.

    Qualification: Its residual lensing B-mode power averaged about 0.48 over the stated angular range, which the authors call the highest delensing efficiency for such a template to date; it has not detected primordial gravitational waves.

    Evidence: source-2026-08-08-011

Sources

  1. arXiv preprint 2608.06343arXiv · primary research

Corrections

No corrections have been recorded for this story.