Record the gate correction in the concept document

The user-facing statement still carried the retired correlation
threshold. Adds the correction, the joint condition that replaces it,
the width diagnosis, and the closure of the shrink-N route.

Co-Authored-By: Claude <noreply@anthropic.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/RANK_RESULTS.md b/RANK_RESULTS.md
index e1c4343..0e481b9 100644
--- a/RANK_RESULTS.md
+++ b/RANK_RESULTS.md
@@ -91,6 +91,18 @@ segmentation and nothing over using fewer segments. This confirms from a new
 angle what the earlier oracle-box comparison found: **segmentation is not the
 constraint on photographs.**
 
+The correlation column in that table should be read against a noise floor.
+Moving the segmentation eigendecomposition from CPU to GPU changes nothing in
+the recipe, yet re-deriving segments through it takes the baseline correlation
+from 0.6559 to 0.6767 — the eigenvectors differ in sign and, where eigenvalues
+are near-degenerate, in rotation, so the clustering that follows lands
+differently. **Segmentation reseeding is worth about 0.02 in correlation**, so
+the 6-versus-16-segment and oracle-box differences in that table are inside
+the noise and only the shared counts distinguish them. The session's headline
+movements, 0.656 to 0.716 to 0.725, are three times the floor. The pipeline
+itself is unchanged: run against the original CPU-derived segments it
+reproduces 0.6559 exactly.
+
 The text side does move it, and saturates:
 
 | Text vector dimension | text eff. rank | ρ | shared |