Pith Number

pith:FWHHOW5O

pith:2013:FWHHOW5O6J6OTCZBVZ5MLK2CWC

not attested not anchored not stored refs pending

Universal central extensions in semi-abelian categories

Jose Manuel Casas, Tim Van der Linden

arxiv:1302.5501 v1 · 2013-02-22 · 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{FWHHOW5O6J6OTCZBVZ5MLK2CWC}

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	2026-05-18T02:54:53.805863Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

2d8e775baef27ce98b21ae7ac5ab42b0a79d42f33852ebf5d4cd96f20e80c043

Aliases

arxiv: 1302.5501 · arxiv_version: 1302.5501v1 · doi: 10.48550/arxiv.1302.5501 · pith_short_12: FWHHOW5O6J6O · pith_short_16: FWHHOW5O6J6OTCZB · pith_short_8: FWHHOW5O

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/FWHHOW5O6J6OTCZBVZ5MLK2CWC \
  | 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: 2d8e775baef27ce98b21ae7ac5ab42b0a79d42f33852ebf5d4cd96f20e80c043

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "841287696c2fef41acc9dfabd1304ae8e22033db893dececd258c559171b2849",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.CT",
    "submitted_at": "2013-02-22T07:15:57Z",
    "title_canon_sha256": "d252a5096c3b4446e065e5c227169aeb25f45063260b65931c738801e076fc97"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1302.5501",
    "kind": "arxiv",
    "version": 1
  }
}