Predictions→ ALP Birefringence
ALP Birefringence
Axion-like particle field evolution through the bounce predicts a specific CMB polarization rotation angle β = 0.27°. The observed Eskilt 2023 combined measurement is β = 0.342° ± 0.094° (3.6σ) — consistent at 0.8σ.
Supporting
β = 0.27°
ECH (ALP field evolution)
LiteBIRD (~2032)
Current Constraint
Observed: β = 0.342° ± 0.094° (3.6σ, Planck+WMAP combined). Our prediction: 0.27°. Consistent at 0.8σ. ACT H200 measurement: β = 17.4° ± 12.1° (systematic-dominated — needs NaMaster).
Key Results
- ALP prediction β = 0.27° from field evolution through bounce
- Matches 3.6σ observed signal (0.342° ± 0.094°) at 0.8σ
- ACT H200 measurement dominated by foreground systematics
- Birefringence simulation validated: injected 0.27°, recovered 0.261° ± 0.037°