Pith Number

pith:NZ4K4VGS

pith:2018:NZ4K4VGSJC5U5XIWGCFW4DPUGP

not attested not anchored not stored refs pending

Twistor lines on algebraic surfaces

Amedeo Altavilla, Edoardo Ballico

arxiv:1802.06697 v3 · 2018-02-19 · math.AG · math.DG

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{NZ4K4VGSJC5U5XIWGCFW4DPUGP}

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	2026-05-17T23:57:07.687604Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

6e78ae54d248bb4edd16308b6e0df433d166599c49553dc42e7fe019ae616e8b

Aliases

arxiv: 1802.06697 · arxiv_version: 1802.06697v3 · doi: 10.48550/arxiv.1802.06697 · pith_short_12: NZ4K4VGSJC5U · pith_short_16: NZ4K4VGSJC5U5XIW · pith_short_8: NZ4K4VGS

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/NZ4K4VGSJC5U5XIWGCFW4DPUGP \
  | 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: 6e78ae54d248bb4edd16308b6e0df433d166599c49553dc42e7fe019ae616e8b

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "ad91d831cdfc2e6f812158183cbf06772ff0f505faaeeb67464359930d502bd0",
    "cross_cats_sorted": [
      "math.DG"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.AG",
    "submitted_at": "2018-02-19T16:48:36Z",
    "title_canon_sha256": "f2621799935926e67fb0d8e05f8c42f13ee736a5ca284dda92cda767d201fda0"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1802.06697",
    "kind": "arxiv",
    "version": 3
  }
}