Pith Number

pith:R2W474CS

pith:2021:R2W474CSN3Z4GRFEX5JSENO7SX

not attested not anchored not stored refs pending

PC4 at Age 40

Michael Freedman

arxiv:2101.10519 v1 · 2021-01-26 · math.GT · math.HO

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{R2W474CSN3Z4GRFEX5JSENO7SX}

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	2026-07-05T02:09:59.369009Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

8eadcff0526ef3c344a4bf532235df95f9738b2f8aadad3a89660749c195141f

Aliases

arxiv: 2101.10519 · arxiv_version: 2101.10519v1 · doi: 10.48550/arxiv.2101.10519 · pith_short_12: R2W474CSN3Z4 · pith_short_16: R2W474CSN3Z4GRFE · pith_short_8: R2W474CS

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/R2W474CSN3Z4GRFEX5JSENO7SX \
  | 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: 8eadcff0526ef3c344a4bf532235df95f9738b2f8aadad3a89660749c195141f

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "562a76a2767168b4771d39c5f5a3c6299ef473c2946e85cf8cbf0f66325b1041",
    "cross_cats_sorted": [
      "math.HO"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "math.GT",
    "submitted_at": "2021-01-26T02:18:16Z",
    "title_canon_sha256": "c60ac3d885bf2c260a717a7ba6b76b71f6f347d74a85a90948784a3684e7fe32"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2101.10519",
    "kind": "arxiv",
    "version": 1
  }
}