Pith Number

pith:7ZTPKEL7

pith:2009:7ZTPKEL7JKJWVOJGK3OGHF6QQB

not attested not anchored not stored refs pending

Minimization of $\lambda_2(\Omega)$ with a perimeter constraint

Antoine Henrot (IECN, Dorin Bucur (LAMA), Giuseppe Buttazzo, Inria Lorraine / Iecn / Mmas)

arxiv:0904.2193 v2 · 2009-04-14 · math.AP · math.OC · math.SP

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{7ZTPKEL7JKJWVOJGK3OGHF6QQB}

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	2026-05-18T04:34:46.334630Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

fe66f5117f4a936ab92656dc6397d080746fbcbeb6d82d1fedb1dec16887f0a2

Aliases

arxiv: 0904.2193 · arxiv_version: 0904.2193v2 · doi: 10.48550/arxiv.0904.2193 · pith_short_12: 7ZTPKEL7JKJW · pith_short_16: 7ZTPKEL7JKJWVOJG · pith_short_8: 7ZTPKEL7

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/7ZTPKEL7JKJWVOJGK3OGHF6QQB \
  | 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: fe66f5117f4a936ab92656dc6397d080746fbcbeb6d82d1fedb1dec16887f0a2

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "54423d43bd723cd6bec887ad13a5d10001bc4a6f137b2ba28695775d1d6e4da1",
    "cross_cats_sorted": [
      "math.OC",
      "math.SP"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.AP",
    "submitted_at": "2009-04-14T20:12:12Z",
    "title_canon_sha256": "184c76155c63427c6f256fb5b858c2e00a706e9be811d8b672c2a118173963d2"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0904.2193",
    "kind": "arxiv",
    "version": 2
  }
}