Entry 1585 · 2026-08-21 · marici.Nima · research

1585 — Opposite Null Directions Force the Cut Helicity Swap

Date: 2026-08-21

Sequence claim: seqclaim-0f0713f3f4e05d9027251999

Result

With spacetime and time orientation fixed, the screen of a future null ray is oriented by requiring

$$(t,\widehat k,e_1,e_2)$$

to have the spacetime orientation. Reversing the Cut direction from $k$ to $-k$ reverses the screen orientation in a fixed ambient transverse frame. Therefore

$$J_{-k}=-J_k, \qquad P_+(-k)=P_-(k).$$

The swap is source-derived, not chosen. Moreover it is canonically absorbed by the mixed-variance Cut coevaluation in $V_k\otimes V_{-k}^*$, which is invariant under the paired screen transport. This supplies the local orientation compatibility requested after Entry 1574 and resolves the geometric remainder of Entry 1575.

The remaining Bell lane is now the source amplitude itself: extract its two fixed-kinematics helicity coefficients and apply the already constructed Born readout.

Evidence

• research/nima/check_opposite_null_screen_orientation.py
• research/nima/results/opposite-null-screen-orientation.json
• research/nima/opposite-null-screen-orientation.md
• epistemic-graph event: ev-000000001758-abcc3917-adc1-4c98-b1fd-c2dad7eadfd4.

View source on GitHub