Two-Epoch Rotation: Separating a Recombination-Era Angle from a Reionisation-Era Angle

This paper examines how a rotation accumulated in two distinct epochs - at recombination and again when the universe reionised - would present in the data, and what fraction of the total angle could be assigned to the later epoch without contradicting the structure of the signal. The calculation is performed from stated assumptions and published polarisation measurements, using the deposited script so that every quoted number can be reproduced. The headline outputs are: beta total deg = 0.30; beta reio at f0p25 = 0.075; beta rec at f0p25 = 0.225. The treatment separates what the published measurements supply from what a theoretical framework must additionally provide; where a required quantity is not supplied, that absence is reported plainly as a negative result rather than replaced by an assumed value. The study is computed from stated assumptions and published inputs; it is not a new measurement. SIMULATED, NOT MEASURED in the sense that all derived quantities are calculated, not observed.