Pith Number

pith:YCS2AFUN

pith:2009:YCS2AFUNVGQR3TJ2NI4CTENRWV

not attested not anchored not stored refs pending

The Schur multiplier, profinite completions and decidability

Martin R Bridson

arxiv:0907.5010 v1 · 2009-07-28 · math.GR

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{YCS2AFUNVGQR3TJ2NI4CTENRWV}

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	2026-05-18T02:58:02.917258Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

c0a5a0168da9a11dcd3a6a382991b1b561e524ca7d7b7b3b8a4def28bff0869b

Aliases

arxiv: 0907.5010 · arxiv_version: 0907.5010v1 · doi: 10.48550/arxiv.0907.5010 · pith_short_12: YCS2AFUNVGQR · pith_short_16: YCS2AFUNVGQR3TJ2 · pith_short_8: YCS2AFUN

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/YCS2AFUNVGQR3TJ2NI4CTENRWV \
  | 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: c0a5a0168da9a11dcd3a6a382991b1b561e524ca7d7b7b3b8a4def28bff0869b

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "04bfe0d90c8b785a7cfb8ecf82057a106ffb229458bf8ab2b4701dd81e8bff04",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.GR",
    "submitted_at": "2009-07-28T22:05:45Z",
    "title_canon_sha256": "e4647e02e5ee170ae924591aa6e1266d1730dee52442a8909c3dd5234ac62cfa"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0907.5010",
    "kind": "arxiv",
    "version": 1
  }
}