Pith Number

pith:HPTHBJJU

pith:2018:HPTHBJJUNKI5YQ2WYU6GFYFZXO

not attested not anchored not stored refs pending

Serre's Property FA for automorphism groups of free products

Nils Leder

arxiv:1810.06287 v1 · 2018-10-15 · 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{HPTHBJJUNKI5YQ2WYU6GFYFZXO}

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.

Cited by

1 paper in Pith

Serre's Property (FA) for automorphism groups of free products

Receipt and verification

First computed	2026-05-18T00:03:20.917695Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

3be670a5346a91dc4356c53c62e0b9bb8c4e9a4fb24775b46ae25ecde1a73457

Aliases

arxiv: 1810.06287 · arxiv_version: 1810.06287v1 · doi: 10.48550/arxiv.1810.06287 · pith_short_12: HPTHBJJUNKI5 · pith_short_16: HPTHBJJUNKI5YQ2W · pith_short_8: HPTHBJJU

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/HPTHBJJUNKI5YQ2WYU6GFYFZXO \
  | 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: 3be670a5346a91dc4356c53c62e0b9bb8c4e9a4fb24775b46ae25ecde1a73457

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "55db5ca05f5a96c587a2bec7e35c6e62bba82634b72a9476847451010c7a7a5b",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.GR",
    "submitted_at": "2018-10-15T11:43:50Z",
    "title_canon_sha256": "9561c4b412854541adc4e745f183a215de2db568d813cacc2b7bb9c3b860e57f"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1810.06287",
    "kind": "arxiv",
    "version": 1
  }
}