Pith Number

pith:JDCNG3E3

pith:2019:JDCNG3E3HV24TP6UUDQHQQ5E53

not attested not anchored not stored refs pending

Systolically extremal nonpositively curved surfaces are flat with finitely many singularities

Mikhail Katz, Stephane Sabourau

arxiv:1904.00730 v1 · 2019-04-01 · math.DG

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{JDCNG3E3HV24TP6UUDQHQQ5E53}

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	2026-05-17T23:46:17.968334Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

48c4d36c9b3d75c9bfd4a0e07843a4eeee93e8a858ed9f7c86399dd4f6b40568

Aliases

arxiv: 1904.00730 · arxiv_version: 1904.00730v1 · doi: 10.48550/arxiv.1904.00730 · pith_short_12: JDCNG3E3HV24 · pith_short_16: JDCNG3E3HV24TP6U · pith_short_8: JDCNG3E3

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/JDCNG3E3HV24TP6UUDQHQQ5E53 \
  | 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: 48c4d36c9b3d75c9bfd4a0e07843a4eeee93e8a858ed9f7c86399dd4f6b40568

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "9982faa31ba3b2dffaf7d36318a091184936e2afaa60c341858acb24732ddb27",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.DG",
    "submitted_at": "2019-04-01T12:23:52Z",
    "title_canon_sha256": "302e4f8f526ee82575a4d2f21c401d454c77f45e6b2da386baf8dab7135f36d2"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1904.00730",
    "kind": "arxiv",
    "version": 1
  }
}