Pith Number

pith:PVV2LJFB

pith:2021:PVV2LJFBQ2ZARFVQRQNQNUXIFK

not attested not anchored not stored refs pending

Efficient computation of matrix-vector products with full observation weighting matrices in data assimilation

Guannan Hu, Sarah L. Dance

arxiv:2109.02091 v1 · 2021-09-05 · math.NA · cs.NA

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{PVV2LJFBQ2ZARFVQRQNQNUXIFK}

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	2026-07-05T03:45:42.372984Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

7d6ba5a4a186b20896b08c1b06d2e82a8e8ff9bfa957903680fde28542663417

Aliases

arxiv: 2109.02091 · arxiv_version: 2109.02091v1 · doi: 10.48550/arxiv.2109.02091 · pith_short_12: PVV2LJFBQ2ZA · pith_short_16: PVV2LJFBQ2ZARFVQ · pith_short_8: PVV2LJFB

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/PVV2LJFBQ2ZARFVQRQNQNUXIFK \
  | 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: 7d6ba5a4a186b20896b08c1b06d2e82a8e8ff9bfa957903680fde28542663417

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "ad684526c0d6e287a044d32e03e74e3ff33d846c6f2f6d51b16004d6910d9860",
    "cross_cats_sorted": [
      "cs.NA"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "math.NA",
    "submitted_at": "2021-09-05T14:51:01Z",
    "title_canon_sha256": "039d3cc44d720258b383321ef25c78af97aa6c34a444a62051b0e873234b87df"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2109.02091",
    "kind": "arxiv",
    "version": 1
  }
}