Higher-Dimensional BLAST Hypothesis (HDBLAST): Status snapshot v8 (2026-04-10) — authoritativeness closure, exact witness routes, and compact fallback ladders for PTA low-frequency stochastic GW background analyses

This release is a status/methods snapshot for the HDBLAST ("Higher-Dimensional BLAST") program. It does not claim a detection or proof of a higher-dimensional-blast origin. Instead, it documents three concrete outcomes from the current working state.

First, it records a corpus-level authoritativeness closure. Repeated exact-filename IPTA_DR2B_TOP5_* files found in the scanned archive corpus are non-authoritative by content: the repeated payloads have one unique SHA256 per basename and the repeated raw-zip payload includes explicit stand-in metadata (including authoritative=false / working stand-in wording).

Second, it documents exact witness routes and compact fallback ladders derived from the shared EPTA/IPTA packet. The current compact default is Shoulder7, while Seed8 is retained only when full physical seed-triplet continuity is explicitly required. The release also includes witness-rank and compact-fallback summaries that clarify the current route ladder without overclaiming.

Third, it keeps the claim boundary explicit. The decisive missing object remains an authoritative IPTA_DR2B_TOP5_* HD export plus one explicit W-definition line. Until that object exists, the HDBLAST program remains a falsifiable hypothesis / research program rather than a confirmed origin claim.

Status: research snapshot / methods update. Not peer reviewed.

# Key deliverables in this version

- Curated public-safe status snapshot (`HDBLAST_STATUS_SNAPSHOT_V8_20260410_ZENODO_READY.zip`)
- Archive forensic closure note plus machine-readable occurrence and hash tables
- Exact compact-route ladder summary (`Shoulder7`, `Seed8`, `NearFull9`, `Triplet9`, `TSWP65`)
- Machine-readable route-ladder JSON
- Release notes and citation file

# Explicit status / claim boundary

- No authoritative `IPTA_DR2B_TOP5_*` HD export is in hand.
- No explicit `W` definition line is in hand.
- Repeated exact-filename `IPTA_DR2B_TOP5_*` files in the current archive corpus are treated as non-authoritative by content unless stated otherwise explicitly in writing.
- This release is a status snapshot and methods update, not a claim of discovery.

# Files in the main ZIP

- `README_HDBLAST_STATUS_SNAPSHOT_V8_20260410.md`
- `HDBLAST_STATUS_SNAPSHOT_V8_20260410.md`
- `HDBLAST_RELEASE_NOTES_V8_20260410.md`
- `HDBLAST_AUTHORITATIVENESS_CLOSURE_V8_20260410.md`
- `HDBLAST_EMPIRICAL_ROUTE_LADDER_V8_20260410.md`
- `HDBLAST_ROUTE_LADDER_V8_20260410.json`
- `HDBLAST_CURRENT_PACKET_SUMMARY_V8_20260410.md`
- `HDBLAST_SIDECAR_BOUNDARY_V8_20260410.md`
- supporting machine-readable summaries and archive tables
- `CITATION.cff`