Planck intermediate results XLIX. Parity-violation constraints from polarization data
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Bibliographic record
Abstract
Parity-violating extensions of the standard electromagnetic theory cause \nin vacuo rotation of the plane of polarization of propagating photons. \nThis effect, also known as cosmic birefringence, has an impact on the \ncosmic microwave background (CMB) anisotropy angular power spectra, \nproducing non-vanishing T-B and E-B correlations that are otherwise null \nwhen parity is a symmetry. Here we present new constraints on an \nisotropic rotation, parametrized by the angle alpha, derived from Planck \n2015 CMB polarization data. To increase the robustness of our analyses, \nwe employ two complementary approaches, in harmonic space and in map \nspace, the latter based on a peak stacking technique. The two approaches \nprovide estimates for alpha that are in agreement within statistical \nuncertainties and are very stable against several consistency tests. \nConsidering the T-B and E-B information jointly, we find alpha = 0 \ndegrees: 31 +/- 0 degrees.05 (stat:) +/- 0 degrees:28 (syst:) from the \nharmonic analysis and alpha = 0 degrees.35 +/- 0 degrees.05 (stat :) 0 \ndegrees.28 (syst :) from the stacking approach. These constraints are \ncompatible with no parity violation and are dominated by the systematic \nuncertainty in the orientation of Planck's polarization-sensitive \nbolometers.
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Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.000 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from it