Marcin Pawlowski 15e876e90a
Correctness pass: derive rho in code, and the absolute vs-1.0 test
Two findings from re-reviewing the fine-delay section.

1. The rho values I put in s3.2a were wrong. The report derives
   rho = f*D_vis with D_vis = hops*delta_max/2 + (hops+1)*ell_mean from
   a MEASURED ell_mean (1.211 slots at N=1000/degree=6), not from the
   link_latency_mean parameter (0.5). Hand-substituting a guessed 1.5
   inflated every value by ~0.04: the band is rho 0.21-0.41, not
   0.25-0.45.

   To stop that recurring, graph_ell_mean moves out of
   rho_boundary_analysis.py into figures_pernode.py, joined by a new
   rho_for() that both scripts and any future quotation go through;
   plot_fine_delay.py now prints the derived rho per delay.

   This also exposed an inconsistency in the existing s3.2 table, which
   rounded delta_max=4 to "rho ~ 0.4" while s3.2a called the same cell
   0.36 and prose elsewhere already used 0.56 for delta_max=8. The s3.2
   column now carries the derived values (0.36/0.56/0.96/1.76).

2. Testing each cell against the exact target 1.0 -- the same question
   the gap test asks, without reference to the other model --
   corroborates the first-fork onset independently. Unrestricted: 1/15
   cells below 1 (t=-2.09, chance). Countable: 4/15, and not scattered
   -- delta_max=4 at U=1, and ALL THREE caps at delta_max=5 (-0.0012 to
   -0.0019, t=-2.5..-3.7). A shortfall appearing at every cap at once,
   only at the top of the band, only under the restricted model, is the
   first-fork cost seen absolutely.

   That makes "one uncle slot is sufficient -- not approximately,
   exactly" too strong as I had written it. s3.2a now states the
   residual (0.1-0.2% at the top of the band, zero below delta_max=3),
   reconciles it with the s1 headline, and notes that since all three
   caps show the same shortfall the residual is not a capacity limit.
   The bound quoted in s1 moves from "below 0.15%" to "<= 0.2%".

Also adds the new run directories to s9's canonical list, which covered
every other study but not these.

Tests: 209 passed. ruff clean.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
2026-08-05 10:34:33 +02:00
..
2026-07-30 18:51:15 +02:00
2026-07-30 18:52:01 +02:00