Pith Number

pith:NHIVU6R3

pith:1997:NHIVU6R3KOJLLVRPFS2LHKIY4P

not attested not anchored not stored refs pending

Contact Cohomology of the Projective Plane

Gary Kennedy, Lars Ernstr\"om

arxiv:alg-geom/9703013 v3 · 1997-03-10 · alg-geom · math.AG

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{NHIVU6R3KOJLLVRPFS2LHKIY4P}

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	2026-05-18T01:09:21.773052Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

69d15a7a3b5392b5d62f2cb4b3a918e3c514b4845b1ec992c96ddf250c907f23

Aliases

arxiv: alg-geom/9703013 · arxiv_version: alg-geom/9703013v3 · doi: 10.48550/arxiv.alg-geom/9703013 · pith_short_12: NHIVU6R3KOJL · pith_short_16: NHIVU6R3KOJLLVRP · pith_short_8: NHIVU6R3

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/NHIVU6R3KOJLLVRPFS2LHKIY4P \
  | 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: 69d15a7a3b5392b5d62f2cb4b3a918e3c514b4845b1ec992c96ddf250c907f23

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "36518e2ac0e1f1e1308026ac87dd8ccdb58387f1c7a580be31a712f5a29c91de",
    "cross_cats_sorted": [
      "math.AG"
    ],
    "license": "",
    "primary_cat": "alg-geom",
    "submitted_at": "1997-03-10T11:36:58Z",
    "title_canon_sha256": "933ee7896c14e9535e53baf137ae163b8f567503bf18ad508b7f46be6088fa2a"
  },
  "schema_version": "1.0",
  "source": {
    "id": "alg-geom/9703013",
    "kind": "arxiv",
    "version": 3
  }
}