Structural Challenge Ledger v2.0
Replaced the v1 Problem Ledger with the v2.0 Structural Challenge Ledger — 214 canonical items across mathematics, physics, life, and metaphysics, source-of-truth in the corpus repo with site projection.
Site release
Program
Results
Corpus
Changes
- Agenda lane: Promoted the Structural Challenge Ledger — 214 canonical items across four domains (38 mathematics, 117 physics including 15 τ-native challenges, 29 life, 30 metaphysics).
- Source-of-truth: Items live in the corpus repo at
corpus/structural-challenge-ledger/items/<domain>/<cluster>/alongside the registry, bibliography, and recovery requirements. The site is now a projection rather than the authoritative source. - Schema: Each item carries domain-prefixed IDs (P001–P102, PN-01–PN-15, LIFE-SC-01–29, M-E3-01–29, MRC-01, S4–S18, F1–F18, CB-*), cluster + ring depth (R0–R6 for physics) or τ-register + ontic requirement (Reg_E/P/D/C, OR1–OR6 for metaphysics), challenge types, and cross-domain links between paired entries.
- v1 retirement — clean cut: Retired the v1 Problem Ledger and Problem Ledger Answers. All v1 URLs (
/program/research-agenda/problem-ledger/*,/results/problem-ledger-answers/*) 301-redirect to the corresponding v2 SCL surfaces. Full v1 snapshot archived inatlas/archive/problem-ledger-v1-snapshot-2026-05-04/. - Cross-domain links: 17 paired-entry cross-domain handoffs surface where the same problem appears in two domains (e.g. Yang-Mills as both a math Clay problem and a physics R0 foundational entry; abiogenesis on both physics R6 boundary and life origin clusters).
- Navigation: Added the Structural Challenge Ledger to the Agenda left-rail tree alongside other agenda surfaces.