Pith Number

pith:WUUHRXQC

pith:2017:WUUHRXQCMSV6VLDV2SJ5YIKKZR

not attested not anchored not stored refs pending

On the use of the saddle formulation in weakly-constrained 4D-VAR data assimilation

E. Simon, Ph. L. Toint, S. Gratton, S. G\"urol

arxiv:1709.06383 v1 · 2017-09-19 · math.NA · cs.NA · 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{WUUHRXQCMSV6VLDV2SJ5YIKKZR}

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	2026-06-04T19:10:59.988760Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

b52878de0264abeaac75d493dc214acc677d8af8448f6f19fb487aa70b812a13

Aliases

arxiv: 1709.06383 · arxiv_version: 1709.06383v1 · doi: 10.48550/arxiv.1709.06383 · pith_short_12: WUUHRXQCMSV6 · pith_short_16: WUUHRXQCMSV6VLDV · pith_short_8: WUUHRXQC

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/WUUHRXQCMSV6VLDV2SJ5YIKKZR \
  | 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: b52878de0264abeaac75d493dc214acc677d8af8448f6f19fb487aa70b812a13

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "d03807326fba18e4d5a1b3bcbf38836d4407e728325caecec15a6f05a7fc5363",
    "cross_cats_sorted": [
      "cs.NA",
      "math.OC"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.NA",
    "submitted_at": "2017-09-19T12:59:54Z",
    "title_canon_sha256": "b45ec25a755e5b8f92565ffa3157462830158f7d2cda84f60ae7abe86f8a4b18"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1709.06383",
    "kind": "arxiv",
    "version": 1
  }
}