Pith Number

pith:BQACSDZB

pith:2017:BQACSDZB3MSOWNZAAS4BJJY622

not attested not anchored not stored refs pending

Engel groups and universal surgery models

Michael Freedman, Vyacheslav Krushkal

arxiv:1707.07800 v1 · 2017-07-25 · math.GT

Open paper page JSON Open Graph Bundle Merged state Verified badge What is a Pith Number?

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{BQACSDZB3MSOWNZAAS4BJJY622}

Prints a linked badge after your title and injects PDF metadata. Compiles on arXiv. Learn more · Embed verified badge

Record completeness

1 Bitcoin timestamp

2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

✓ Portable graph bundle live · download bundle · merged state

The bundle contains the canonical record plus signed events. A mirror can host it anywhere and recompute the same current state with the deterministic merge algorithm.

Receipt and verification

First computed	2026-07-05T03:18:22.869770Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

0c00290f21db24eb372004b814a71ed6ad64a4ea68ae33448ecd84d84ba61ef4

Aliases

arxiv: 1707.07800 · arxiv_version: 1707.07800v1 · doi: 10.48550/arxiv.1707.07800 · pith_short_12: BQACSDZB3MSO · pith_short_16: BQACSDZB3MSOWNZA · pith_short_8: BQACSDZB

Agent API

Resolver JSON Graph JSON Events JSON Schema Signing key

Verify this Pith Number yourself

curl -sH 'Accept: application/ld+json' https://pith.science/pith/BQACSDZB3MSOWNZAAS4BJJY622 \
  | jq -c '.canonical_record' \
  | python3 -c "import sys,json,hashlib; b=json.dumps(json.loads(sys.stdin.read()), sort_keys=True, separators=(',',':'), ensure_ascii=False).encode(); print(hashlib.sha256(b).hexdigest())"
# expect: 0c00290f21db24eb372004b814a71ed6ad64a4ea68ae33448ecd84d84ba61ef4

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "3ba55f7c7cee0be19a25fa11cac267856723d8b2fc9a9a22d16f15782b2c0e81",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.GT",
    "submitted_at": "2017-07-25T03:15:26Z",
    "title_canon_sha256": "36689a04c46747bdb8244e1a899ad080c75a85191c00297470e5949d77a8b511"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1707.07800",
    "kind": "arxiv",
    "version": 1
  }
}