Scale-Dependent and Anisotropic Cosmic Birefringence: 8.5 σ Isotropic and 4–5 σ Directional Rotation in Planck Polarization Data

This dataset contains the analysis code, data, and figures supporting the detection of a scale-dependent and anisotropic rotation (α) of the linear polarization plane in the Cosmic Microwave Background (CMB). Results are derived from Planck 2018 SMICA and NILC component-separated maps over multipoles ℓ = 500–1500. Using linearized EB estimators with a quantitative q-mask (f_sky ≈ 0.467), α is measured per multipole band and combined across maps via inverse-variance weighting. The lowest multipole band (ℓ = 500–800) shows an isotropic rotation of α = 0.232 ± 0.027 degrees (8.5 σ), decreasing to α = 0.030 ± 0.013 degrees for ℓ = 1100–1500. A hemispheric analysis reveals a statistically significant North–South dipole Δα ≈ 2.3 degrees (4–5 σ). The files include combined α(ℓ) band results, hemispheric Δα estimates, reproducibility scripts, and figure outputs. These materials reproduce the findings reported in the companion publication and allow independent verification using Planck 2018 data. Original archival record hosted by CERN Zenodo: https://doi.org/10.5281/zenodo.17317397 License: Creative Commons Attribution 4.0 International (CC BY 4.0). Version 1.1 — Validation Bundle