Listening Beyond Four Dimensions: Higher-Dimensional Blast — vLASTMILE+ Canonical Snapshot & Tool-Kit

NEXTLEVEL higher‑D blast (status + tools) — This Zenodo record collects the current status of a falsifiable higher‑dimensional “blast” scenario for the origin of our observable Universe. In this picture, a short and violent episode in a higher‑D phase seeds a cosmological stochastic gravitational‑wave background (SGWB) with a smooth broken power‑law (SBPL) spectrum whose knee lies in the nanohertz pulsar‑timing‑array (PTA) band. v22 update: adds shared-knee coherence, curvature/leave-one-out, and covariance-sensitivity diagnostics; updates ShortPaper v10 and GrandStatus v18. This “vLASTMILE+” release provides: • a referee‑friendly snapshot (ShortPaper PDF + TalkDeck), • a minimal end‑to‑end reproduction path for the headline PTA‑band screening gates, • a machine‑readable status summary (GrandStatus JSON), • the key input tables and plots used in the screening. Canonical SBPL parameters (PTA‑amplitude model): • f_k = 3.16e-8 Hz, Ω_k = 8.00e-9, α1 = 3.0, α2 = −2.0, Δ = 2.0. Headline PTA‑band results (binned‑Gaussian free‑spectrum screening; lower BIC is better): • ΔBIC(SMBHB(β=2/3) − SBPL_scan) = 26.21 → log10 BF ≈ 5.69 (SBPL strongly favored). • ΔBIC(PL_free − SBPL_scan) = 13.56 → log10 BF ≈ 2.94 (SBPL favored). • Curvature diagnostic: ΔBIC(linear − quadratic) = 8.08 (≈3.2σ). Cross‑coherence (“same knee”) checks across PTA collaborations (common prior): • PCI_median ≈ 0.866 (PASS; threshold 0.80). • Shared‑knee evidence (all PTAs share f_k): log10 BF ≈ 1.07 (BF ≈ 11.7). Early‑Universe consistency (for the canonical spectrum shape): • Physical ΔN_eff ≈ 7.1e-4 (well below typical BBN/CMB guardrails O(0.06–0.3)). • Multi‑band safety: Ω_gw(25 Hz) ≈ 2.3e-35 (far below LVK O4a isotropic bounds). Important caveat: PTA model screening and BIC/BF numbers here use a binned‑Gaussian approximation of published PTA free‑spectrum points. This version includes leave‑one‑out and covariance‑sensitivity diagnostics showing how evidence can degrade under stronger assumed bin‑to‑bin correlations. Main files: • HDBLAST_ZENODO_UPLOAD_BUNDLE_REALONLY_v22_20251217.zip — full reproducibility bundle • HDBLAST_ShortPaper_v10.pdf — short paper • HDBLAST_TalkDeck_v1.pptx — talk deck • HDBLAST_GrandStatus_BlastOnly_v18.json — scoreboard / gates / numbers • HDBLAST_DATA_REQUEST_v2.md — data needed for next‑level tests