Pith Number

pith:HHDSUNYG

pith:2019:HHDSUNYG5GLTOMAQHLXECI4YOZ

not attested not anchored not stored refs pending

L2 Observers for a Class of Nonlinear Systems with Unknown Inputs

Ankush Chakrabarty, Martin Corless

arxiv:1902.08288 v1 · 2019-02-21 · cs.SY · math.DS · 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{HHDSUNYG5GLTOMAQHLXECI4YOZ}

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	2026-05-17T23:52:57.773577Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

39c72a3706e9973730103aee412398767a8f38c4062c999a1df91583566e06bc

Aliases

arxiv: 1902.08288 · arxiv_version: 1902.08288v1 · doi: 10.48550/arxiv.1902.08288 · pith_short_12: HHDSUNYG5GLT · pith_short_16: HHDSUNYG5GLTOMAQ · pith_short_8: HHDSUNYG

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/HHDSUNYG5GLTOMAQHLXECI4YOZ \
  | 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: 39c72a3706e9973730103aee412398767a8f38c4062c999a1df91583566e06bc

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "71d61a59ed8df7370b175e597586488f533a7a80453362eb3c611f5b139387e3",
    "cross_cats_sorted": [
      "math.DS",
      "math.OC"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "cs.SY",
    "submitted_at": "2019-02-21T22:24:33Z",
    "title_canon_sha256": "2444e1fb855482e8f5d6cd394a40dd54f2380e4b36fa03f998e01647ed39fac0"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1902.08288",
    "kind": "arxiv",
    "version": 1
  }
}