Pith Number

pith:OBSI4VFJ

pith:2010:OBSI4VFJC2BZ44MBQHCSP2VMJC

not attested not anchored not stored refs pending

A class of groups for which every action is W*-superrigid

Cyril Houdayer, Sorin Popa, Stefaan Vaes

arxiv:1010.5077 v3 · 2010-10-25 · math.OA · math.DS · 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{OBSI4VFJC2BZ44MBQHCSP2VMJC}

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	2026-05-18T03:11:58.483508Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

70648e54a916839e718181c527eaac4892a0e17a5b30fda4e0e3ed4e04e7ca31

Aliases

arxiv: 1010.5077 · arxiv_version: 1010.5077v3 · doi: 10.48550/arxiv.1010.5077 · pith_short_12: OBSI4VFJC2BZ · pith_short_16: OBSI4VFJC2BZ44MB · pith_short_8: OBSI4VFJ

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/OBSI4VFJC2BZ44MBQHCSP2VMJC \
  | 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: 70648e54a916839e718181c527eaac4892a0e17a5b30fda4e0e3ed4e04e7ca31

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "7cfbc82cdff48c268c75690a53030bca52ffee1863d5a94c3b7c57602f7dd7e8",
    "cross_cats_sorted": [
      "math.DS",
      "math.GR"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.OA",
    "submitted_at": "2010-10-25T10:16:56Z",
    "title_canon_sha256": "8cb2f11d2aa14e53760a9aa5be1e7e17e7bb4155c8c3c09175d48b35d8f09e27"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1010.5077",
    "kind": "arxiv",
    "version": 3
  }
}