Track A — Bounce vs. inflation

Lead result

$f NL$ ^local = −35/16 → $f NL$ ^after ∈ [−0.65, −0.50]

The exact matter-contraction amplitude f_NL^local = −35/16 is confirmed by an independent from-scratch in-in computation, which also locates Cai et al. (2009)'s published −35/8 as a uniform missing factor of 2, not a competing result. Transmitted through an explicit nonsingular bounce (the bounce's own cubic term, Δf_NL^bounce = −(5/24)ρ_B), the amplitude becomes f_NL^after ∈ [−0.65, −0.50] across three background choices — the number a survey would actually see.

derived

Channels & tests

Channel	Prediction	Current data	Evidence	Receipt
Pulsar timing array (nHz stochastic background)	Bounce-sourced scalar-induced GW spectrum, γ_pred = 5.07.	Ω_GW h²(f_yr) = 1.45e−23 — 14.3 dex below the NANOGrav 15-yr signal.	null	SIGW_NHZ_NOTE_2026-09-04.md
Primordial black holes	Bounce-sourced Δ²_ζ produces an observable PBH abundance.	f_PBH = 0 — 7.0 dex short of a detectable population.	null	inlab_delta2_zeta_2026-09-03
High-z PNG / early-SMBH seeds	A broadband early-SMBH-seed amplitude from bounce non-Gaussianity.	FIRAS excludes the amplitude by roughly 1.8e3×.	null	inlab_delta2_zeta_2026-09-03
LSS bispectrum (SPHEREx-era)	f_NL^after ∈ [−0.65, −0.50], transmitted through the bounce.	Reachable but not separable from ΛCDM at 0.7–0.9σ with SPHEREx-class survey sensitivity.	open	SSOT/paper-a3m/status.md

Works in this track

Multi-channel tests of the matter-bounce prediction f_NL = −35/16 and a joint (r, f_NL) no-go for single-field matter bouncesA joint tensor-and-non-Gaussianity no-go for single-field matter bounces, with a viable curvaton routev3M.0.24 · 75%An Independent Confirmation of f_NL = −35/16 for Matter-Dominated ContractionAn independent confirmation of f_NL = −35/16 for matter-dominated contractionv2L.0.2 · 20%

What is still open

Ledger row 9 — bounce-scale enhancement at kη_B ~ 1The only remaining non-null route for the PTA/PBH channels; a science decision here is required before another review round (directive R2).

A3-4(r) — remaining multi-channel robustness checkOpen at end of the 2026-09-04 session; tracked in NEXT_SCIENCE_LEDGER.md.

A2 — nonlinear transmission research briefNot yet a complete manuscript; the transmission result folded into A3M so far covers the bounce's own cubic term only.

Boundary

This track does not claim a measured detection. Three of its four observational channels are closed nulls; the fourth (LSS bispectrum) is reachable but not yet separable from ΛCDM at current survey sensitivity. Readiness on the flagship manuscript (A3M) stands at 75 — R2 verification closed, further rounds require a new science decision.