Pith Number

pith:KSZ4NCZG

pith:2008:KSZ4NCZGJEBWRG4AFHEK44I7U7

not attested not anchored not stored refs pending

The Classifying Space of a Topological 2-Group

Danny Stevenson, John C. Baez

arxiv:0801.3843 v2 · 2008-01-24 · math.AT · math.CT

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{KSZ4NCZGJEBWRG4AFHEK44I7U7}

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	2026-07-04T15:46:49.734813Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

54b3c68b264903689b8029c8ae711fa7ddd5812a4d30cce1a59c7c0bd13c9553

Aliases

arxiv: 0801.3843 · arxiv_version: 0801.3843v2 · doi: 10.48550/arxiv.0801.3843 · pith_short_12: KSZ4NCZGJEBW · pith_short_16: KSZ4NCZGJEBWRG4A · pith_short_8: KSZ4NCZG

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/KSZ4NCZGJEBWRG4AFHEK44I7U7 \
  | 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: 54b3c68b264903689b8029c8ae711fa7ddd5812a4d30cce1a59c7c0bd13c9553

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "dd9d05fd2c20078c76062af4e04f89b5227a6c1562905ebba0345b95cac79af3",
    "cross_cats_sorted": [
      "math.CT"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.AT",
    "submitted_at": "2008-01-24T20:57:03Z",
    "title_canon_sha256": "37f97bba8fcb8850c3b7a207da5ac69c719bf60f8a4aaef765f4cbfe24d82253"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0801.3843",
    "kind": "arxiv",
    "version": 2
  }
}