Pith Number

pith:JYEK7W7H

pith:2008:JYEK7W7HZC3ZOBOG4YCZQR6PSA

not attested not anchored not stored refs pending

Isoperimetric Problems of the Calculus of Variations on Time Scales

Delfim F. M. Torres, Rui A. C. Ferreira

arxiv:0805.0278 v2 · 2008-05-02 · math.OC · math.CA

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{JYEK7W7HZC3ZOBOG4YCZQR6PSA}

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	2026-05-18T03:41:40.633004Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

4e08afdbe7c8b79705c6e6059847cf900c3e2ff915c705fe6c3da78dc388c844

Aliases

arxiv: 0805.0278 · arxiv_version: 0805.0278v2 · doi: 10.48550/arxiv.0805.0278 · pith_short_12: JYEK7W7HZC3Z · pith_short_16: JYEK7W7HZC3ZOBOG · pith_short_8: JYEK7W7H

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/JYEK7W7HZC3ZOBOG4YCZQR6PSA \
  | 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: 4e08afdbe7c8b79705c6e6059847cf900c3e2ff915c705fe6c3da78dc388c844

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "61424cf656ac7e502f4916d5dfb77b851004340cbf5f61e0be70a11eafa686b9",
    "cross_cats_sorted": [
      "math.CA"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.OC",
    "submitted_at": "2008-05-02T18:13:57Z",
    "title_canon_sha256": "a9c9b721b3b88bc331664c7f8b49ba1a5bb06a706c8d7cfbe1be673eb5ed942b"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0805.0278",
    "kind": "arxiv",
    "version": 2
  }
}