Pith Number

pith:UBAYP7JU

pith:2009:UBAYP7JUJGAJ2OCSKXGNLER2PM

not attested not anchored not stored refs pending

A note on the Hitchin-Thorpe inequality and Ricci flow on 4-manifolds

Yuguang Zhang, Zhenlei Zhang

arxiv:0903.2539 v4 · 2009-03-14 · 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{UBAYP7JUJGAJ2OCSKXGNLER2PM}

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	2026-05-18T04:27:25.747414Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

a04187fd3449809d385255ccd5923a7b1ba120c423899ecc8aad445e6b6c549f

Aliases

arxiv: 0903.2539 · arxiv_version: 0903.2539v4 · doi: 10.48550/arxiv.0903.2539 · pith_short_12: UBAYP7JUJGAJ · pith_short_16: UBAYP7JUJGAJ2OCS · pith_short_8: UBAYP7JU

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/UBAYP7JUJGAJ2OCSKXGNLER2PM \
  | 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: a04187fd3449809d385255ccd5923a7b1ba120c423899ecc8aad445e6b6c549f

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "b7300803df178b518fcb9943a8a51273819c9bef7bddec4be4d94547c5d1b2a3",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.DG",
    "submitted_at": "2009-03-14T11:39:29Z",
    "title_canon_sha256": "7c5eacd321ab3f21423b673ac39a6c208b12282ca73ea55cd578fc8777928633"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0903.2539",
    "kind": "arxiv",
    "version": 4
  }
}