Pith Number

pith:HQK4PAAF

pith:2009:HQK4PAAFSMUX5JYVNBI3ATSNLV

not attested not anchored not stored refs pending

Topological complexity of collision-free motion planning on surfaces

Daniel C. Cohen, Michael Farber

arxiv:0901.0877 v1 · 2009-01-07 · math.AT · math.GT

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{HQK4PAAFSMUX5JYVNBI3ATSNLV}

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	2026-05-18T04:25:13.435727Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

3c15c7800593297ea7156851b04e4d5d57948eca02c3c8f3faa4d23a73b7a6e5

Aliases

arxiv: 0901.0877 · arxiv_version: 0901.0877v1 · doi: 10.48550/arxiv.0901.0877 · pith_short_12: HQK4PAAFSMUX · pith_short_16: HQK4PAAFSMUX5JYV · pith_short_8: HQK4PAAF

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/HQK4PAAFSMUX5JYVNBI3ATSNLV \
  | 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: 3c15c7800593297ea7156851b04e4d5d57948eca02c3c8f3faa4d23a73b7a6e5

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "9281aa1092b3cfd8e3e655a1cfdd39c3c0b9c4f14c0b1273977e764edddb8865",
    "cross_cats_sorted": [
      "math.GT"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.AT",
    "submitted_at": "2009-01-07T17:16:32Z",
    "title_canon_sha256": "ae3464432c2197da85267bf735f0cba1f258c8ff2e7042c6e476798c3ff638d8"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0901.0877",
    "kind": "arxiv",
    "version": 1
  }
}