Pith Number

pith:E72ONVFD

pith:2021:E72ONVFD47X4KOWOOVXRQASDQP

not attested not anchored not stored refs pending

Second obstruction to pseudoisotopy in dimension 3

Kiyoshi Igusa

arxiv:2112.08293 v1 · 2021-12-15 · math.GT · 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{E72ONVFD47X4KOWOOVXRQASDQP}

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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

Pseudo-isotopy versus isotopy for homeomorphisms of 4-manifolds

Receipt and verification

First computed	2026-07-05T03:41:19.962660Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

27f4e6d4a3e7efc53ace756f18024383e71d3714d10af61f5f165274a1e333b2

Aliases

arxiv: 2112.08293 · arxiv_version: 2112.08293v1 · doi: 10.48550/arxiv.2112.08293 · pith_short_12: E72ONVFD47X4 · pith_short_16: E72ONVFD47X4KOWO · pith_short_8: E72ONVFD

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/E72ONVFD47X4KOWOOVXRQASDQP \
  | 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: 27f4e6d4a3e7efc53ace756f18024383e71d3714d10af61f5f165274a1e333b2

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "16a7e99c018505bc99fc75d0b3483e1fdcd03f89bb7d7385c0cc72cb78c23c0d",
    "cross_cats_sorted": [
      "math.AT"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "math.GT",
    "submitted_at": "2021-12-15T17:37:48Z",
    "title_canon_sha256": "447e56f55461d4f8d748a19df31a099a59dac4377aa4232e0bea1040cbe3a26d"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2112.08293",
    "kind": "arxiv",
    "version": 1
  }
}