USR-2026-0016 · CMB

Both satellites weakly prefer a large-scale cutoff

Both Planck and WMAP weakly prefer a low-ℓ power cutoff (Planck Δχ² = 3.72 ≈ 1.4σ at ℓ_c = 2.6; WMAP ≈ 1.2σ at ℓ_c = 2.5) — a curiosity, not a detection.

PROVISIONAL 1.2-1.4σ — curiosity, not detection re-run & confirmed 2026-07-31 (R0 — David Thompson's CI; independence pending)

Fitting an explicit low-multipole cutoff to each experiment: both prefer one, at nearly the same scale, but only at the 1σ-ish level. Seeded exactly as the scripts print it: a hint.

Falsify-box — how to kill this claim

SURVIVED The 1.4 sigma comes from p = chi2.sf(3.72, df=2) = 0.156 -> 1.42 sigma (run_special_scale.py lines 84-86), which ASSUMES the null distribution of Delta chi^2 is exactly chi^2 with 2 dof. It is not: fit_cutoff (lines 63-70) grid-scans l_c over 120 values in [2,20] and A over 120 values in [0,1] with A hard-bounded at 1, a boundary-constrained scanned-parameter problem, and the fit runs on a full-sky, unmasked, noise-free anafast of the raw map. Calibrate by Monte Carlo: generate >= 10^4 LambdaCDM skies, push each through the identical observed_cl -> fit_cutoff pipeline, and read off the fraction with Delta chi^2 >= 3.72. The claim is DEAD if that fraction exceeds 0.317, i.e. the observed Delta chi^2 = 3.72 fails to reach the MC-calibrated 1 sigma point (which under chi^2_2 would sit at Delta chi^2 = 2.30), because 'both experiments weakly prefer a cutoff at 1.2-1.4 sigma' then collapses to 'both are consistent with no cutoff'. Separately DEAD if refitting with the galaxy mask plus a noise and foreground-residual term drives the best-fit A to >= 0.95 (no suppression) or Delta chi^2 < 1 in either experiment.

Verification record — every quoted number, re-run 2026-07-31

quantitymeasuredverdict
Planck cutoff preference Δχ² = 3.72, ~1.4σ MATCH
Planck ℓ_c 2.6 MATCH
WMAP cutoff preference ~1.2σ CLOSE
WMAP ℓ_c 2.5 MATCH
both experiments prefer cutoff yes, both MATCH
KILL-TEST EXECUTION 2026-07-31 empirical LEE null: map-level 10⁴ sims → 1.43σ; analytic 2×10⁵ sims → 1.45σ; naive χ²(2 dof) said 1.42σ MATCH
why the naive number was accidentally right the (ℓ_c, A) grid-scan look-elsewhere inflation is almost exactly cancelled by the A ∈ [0,1] boundary (~12% of null skies give Δχ² = 0) MATCH

Provenance

script: boundary_seam/run_special_scale.py
script status: PRESENT
datasets: Planck SMICA · WMAP 9-yr ILC · claim-scripts (downloadable from /data — run it yourself)
re-run: 2026-07-31

Status, honestly

kill test EXECUTED 2026-07-31 and SURVIVED as written: the empirical look-elsewhere-corrected significance is 1.43–1.45σ against the naive 1.42σ — the correction is negligible. This status was assigned by hand from the public re-run audit above — it is a judgement made from that evidence, not a number this site computed for itself. What cannot move it is authority: no vote, endorsement, or say-so, from anyone including the maintainer. Independent reproduction would move it; nothing else will.

§ Figures 1 from boundary_seam/run_special_scale.py

What this claim's own script draws. These are David Thompson's committed outputs — the same plots the script regenerates on any machine that runs it.

special_scale.png 84.1 KB download
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