Version 1.3 presents verification results for cosmic birefringence, a rotation of the CMB's linear polarization plane, using Planck 2018 data. The analysis confirms an 8.5σ isotropic rotation and a 5σ directional dipole component, with a rotation angle α(ℓ) decreasing from ≈0.23° to 0.03° between ℓ = 500–1500. The dataset was authored by Amy Condit and last updated on 2026-06-17.
Use Cases
- Test cosmological models based on the confirmed 8.5σ isotropic cosmic birefringence signal.
- Analyze the scale-dependent two-harmonic modulation of the rotation angle α(ℓ) mentioned in the description.
- Investigate the persistent East–West dipole in polarization rotation across different sky regions and masking strategies.
- Validate analysis pipelines using the described calibration and null checks, such as TB/EB spectra ≈ 0.
Strengths
- Verification includes results from multiple component-separation methods (SMICA and NILC) agreeing within ≈0.05°–0.10° per ℓ-bin.
- Robustness tests cover multiple sky regions (|b| = 31°–45°) and apodization scales (2°–3°).
- The analysis recovers injected constant-α (0.25°) simulations within ±0.01°.
Limitations
- Column-level documentation is absent; field semantics must be inferred after download.
- Row count is unknown, which may limit suitability assessment.
Provenance
- Source
- Planck 2018 polarization data.
- Collection Method
- Analysis of cosmic microwave background polarization maps, including verification and robustness tests.
- Freshness
- Last updated 2026-06-17 22:15:34
- Geography
- Full-sky analysis with f_sky ≈ 0.47.