Pith Number

pith:J6UGRTDZ

pith:1997:J6UGRTDZX75LXDSML662VMO7TT

not attested not anchored not stored refs pending

Buildings, group extensions and the cohomology of congruence subgroups

Alejandro Adem

arxiv:math/9702234 v1 · 1997-02-20 · math.GR · 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{J6UGRTDZX75LXDSML662VMO7TT}

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	2026-05-18T01:05:37.096880Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

4fa868cc79bffabb8e4c5fbdaab1df9cef891d4ed49aec2df8d6e8c823b205b2

Aliases

arxiv: math/9702234 · arxiv_version: math/9702234v1 · doi: 10.48550/arxiv.math/9702234 · pith_short_12: J6UGRTDZX75L · pith_short_16: J6UGRTDZX75LXDSM · pith_short_8: J6UGRTDZ

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/J6UGRTDZX75LXDSML662VMO7TT \
  | 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: 4fa868cc79bffabb8e4c5fbdaab1df9cef891d4ed49aec2df8d6e8c823b205b2

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "5d8b3a94644a1c0a374f21a4505fcb09a1c0c9a538be5e99f50a5df80d5ab791",
    "cross_cats_sorted": [
      "math.AT"
    ],
    "license": "",
    "primary_cat": "math.GR",
    "submitted_at": "1997-02-20T00:00:00Z",
    "title_canon_sha256": "f02fdc221fb3b27ef4993bba4697f23a85d1f49aaea1a450f50cbbaf634df3aa"
  },
  "schema_version": "1.0",
  "source": {
    "id": "math/9702234",
    "kind": "arxiv",
    "version": 1
  }
}