Pith Number

pith:NUTQFZJD

pith:2013:NUTQFZJDQN5J7ILSYO4BX2MPFE

not attested not anchored not stored refs pending

Some New Problems in Spectral Optimization

Bozhidar Velichkov, Giuseppe Buttazzo

arxiv:1304.4369 v1 · 2013-04-16 · math.OC

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{NUTQFZJDQN5J7ILSYO4BX2MPFE}

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	2026-05-18T03:27:53.283373Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

6d2702e523837a9fa172c3b81be98f2936e82dff569e75582d75ee8a29e8436a

Aliases

arxiv: 1304.4369 · arxiv_version: 1304.4369v1 · doi: 10.48550/arxiv.1304.4369 · pith_short_12: NUTQFZJDQN5J · pith_short_16: NUTQFZJDQN5J7ILS · pith_short_8: NUTQFZJD

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/NUTQFZJDQN5J7ILSYO4BX2MPFE \
  | 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: 6d2702e523837a9fa172c3b81be98f2936e82dff569e75582d75ee8a29e8436a

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "dde76360d19b05b9d43d7a8fc03b2705964c2848bfe59db76b4c3b41c37d3823",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.OC",
    "submitted_at": "2013-04-16T09:07:50Z",
    "title_canon_sha256": "e5310c93a7863f06e3adf11e03c36c1fc44c88a175dda8a51ccc0098e0fcfcb7"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1304.4369",
    "kind": "arxiv",
    "version": 1
  }
}