Pith Number

pith:QNPC4HUQ

pith:2010:QNPC4HUQUUDVEN2WWKYI2ECQFT

not attested not anchored not stored refs pending

Comparing cohomology obstructions

David Blanc, Hans-Joachim Baues

arxiv:1008.1712 v1 · 2010-08-10 · math.AT

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{QNPC4HUQUUDVEN2WWKYI2ECQFT}

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	2026-05-18T04:42:23.422818Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

835e2e1e90a507523756b2b08d10502cd96e7c2a76bea23b7ada630abe2f29fb

Aliases

arxiv: 1008.1712 · arxiv_version: 1008.1712v1 · doi: 10.48550/arxiv.1008.1712 · pith_short_12: QNPC4HUQUUDV · pith_short_16: QNPC4HUQUUDVEN2W · pith_short_8: QNPC4HUQ

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/QNPC4HUQUUDVEN2WWKYI2ECQFT \
  | 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: 835e2e1e90a507523756b2b08d10502cd96e7c2a76bea23b7ada630abe2f29fb

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "ecc0a858164d04cd6569bc3c18fca0ea62d0dc69298df534ac3c5360b2b42afd",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.AT",
    "submitted_at": "2010-08-10T13:30:26Z",
    "title_canon_sha256": "268f0ec9127e69cd19d903c494bf15b2b2973ae3ccf2c00af93e409fdb1f3cc3"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1008.1712",
    "kind": "arxiv",
    "version": 1
  }
}