Pith Number

pith:NJOKUQHB

pith:2009:NJOKUQHB7FE34FNMHJD6DT2CRJ

not attested not anchored not stored refs pending

Upper motives of algebraic groups and incompressibility of Severi-Brauer varieties

Nikita A. Karpenko

arxiv:0904.2844 v3 · 2009-04-18 · 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{NJOKUQHB7FE34FNMHJD6DT2CRJ}

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	2026-05-18T04:18:34.950820Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

6a5caa40e1f949be15ac3a47e1cf428a6bc5d2a6bc9dec37937af3c1f7c5e856

Aliases

arxiv: 0904.2844 · arxiv_version: 0904.2844v3 · doi: 10.48550/arxiv.0904.2844 · pith_short_12: NJOKUQHB7FE3 · pith_short_16: NJOKUQHB7FE34FNM · pith_short_8: NJOKUQHB

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/NJOKUQHB7FE34FNMHJD6DT2CRJ \
  | 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: 6a5caa40e1f949be15ac3a47e1cf428a6bc5d2a6bc9dec37937af3c1f7c5e856

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "be6e20d2beceef88b9107a6b9ca671af3262434c57119aff9e5399dac3699605",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.AG",
    "submitted_at": "2009-04-18T12:21:38Z",
    "title_canon_sha256": "1489e62107decb6386a4e3214bca3bab414f976b2e273677116a8e50220eb458"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0904.2844",
    "kind": "arxiv",
    "version": 3
  }
}