Pith Number

pith:YSQUGUBQ

pith:2009:YSQUGUBQKVRYJXNFIRBDZAVJ7U

not attested not anchored not stored refs pending

Scl, sails and surgery

Danny Calegari

arxiv:0907.3541 v3 · 2009-07-21 · math.GR · 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{YSQUGUBQKVRYJXNFIRBDZAVJ7U}

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	2026-05-18T02:58:02.939181Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

c4a1435030556384dda544423c82a9fd034d4aee42f0f28d60730cf0b504d917

Aliases

arxiv: 0907.3541 · arxiv_version: 0907.3541v3 · doi: 10.48550/arxiv.0907.3541 · pith_short_12: YSQUGUBQKVRY · pith_short_16: YSQUGUBQKVRYJXNF · pith_short_8: YSQUGUBQ

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/YSQUGUBQKVRYJXNFIRBDZAVJ7U \
  | 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: c4a1435030556384dda544423c82a9fd034d4aee42f0f28d60730cf0b504d917

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "6b18664f62b5cb80cc49209037a1eb6bede5ad6202d3dee321c375b22dc1415d",
    "cross_cats_sorted": [
      "math.GT"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.GR",
    "submitted_at": "2009-07-21T05:21:15Z",
    "title_canon_sha256": "6c88b8e063ac01d5fe6a3dc7e3c24c1e56adcaea9861e1519e63d8d7282befcc"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0907.3541",
    "kind": "arxiv",
    "version": 3
  }
}