Pith Number

pith:XLCDELGY

pith:2021:XLCDELGYLHWKQAR2P5KM7SBZRQ

not attested not anchored not stored refs pending

Randomised preconditioning for the forcing formulation of weak constraint 4D-Var

Amos S. Lawless, Ieva Dau\v{z}ickait\.e, Jennifer A. Scott, Peter Jan van Leeuwen

arxiv:2101.07249 v2 · 2021-01-18 · 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{XLCDELGYLHWKQAR2P5KM7SBZRQ}

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	2026-07-05T03:34:21.739792Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

bac4322cd859eca8023a7f54cfc8398c307d68c3622815055a7da7044044f2c1

Aliases

arxiv: 2101.07249 · arxiv_version: 2101.07249v2 · doi: 10.48550/arxiv.2101.07249 · pith_short_12: XLCDELGYLHWK · pith_short_16: XLCDELGYLHWKQAR2 · pith_short_8: XLCDELGY

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/XLCDELGYLHWKQAR2P5KM7SBZRQ \
  | 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: bac4322cd859eca8023a7f54cfc8398c307d68c3622815055a7da7044044f2c1

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "6c5bdbfe3ed9a3299d42db935b3144a52d8a4a8202c0dd739f22a805b9bf7a7b",
    "cross_cats_sorted": [
      "cs.NA",
      "math.OC"
    ],
    "license": "http://creativecommons.org/licenses/by/4.0/",
    "primary_cat": "math.NA",
    "submitted_at": "2021-01-18T18:57:11Z",
    "title_canon_sha256": "5cbfb93bd5f0e2eafff14394e49b52e8f4e3a308fc7d6160a2e6f32c6b211881"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2101.07249",
    "kind": "arxiv",
    "version": 2
  }
}