Pith Number

pith:FQD3TC6Z

pith:2009:FQD3TC6ZI5R3UKG7L2ECYL6ANV

not attested not anchored not stored refs pending

Krein systems and canonical systems on a finite interval: accelerants with a jump discontinuity at the origin and continuous potentials

A.L. Sakhnovich, D. Alpay, I. Gohberg (Z''L), L. Lerer, M.A. Kaashoek

arxiv:0912.4444 v1 · 2009-12-22 · math.CA · math.SP

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{FQD3TC6ZI5R3UKG7L2ECYL6ANV}

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	2026-05-18T04:25:11.466987Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

2c07b98bd94763ba28df5e882c2fc06d5822c27d39c1ee4b3fefbef4f943db1b

Aliases

arxiv: 0912.4444 · arxiv_version: 0912.4444v1 · doi: 10.48550/arxiv.0912.4444 · pith_short_12: FQD3TC6ZI5R3 · pith_short_16: FQD3TC6ZI5R3UKG7 · pith_short_8: FQD3TC6Z

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/FQD3TC6ZI5R3UKG7L2ECYL6ANV \
  | 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: 2c07b98bd94763ba28df5e882c2fc06d5822c27d39c1ee4b3fefbef4f943db1b

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "e2d8a81c4df75bc150a239f2bcbf5da5d8552a49c60efedd50d9a72c6a5a715d",
    "cross_cats_sorted": [
      "math.SP"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.CA",
    "submitted_at": "2009-12-22T16:41:10Z",
    "title_canon_sha256": "8266cb8bd032ebd142b5a8a285d5b185588489407c18e6b06e8b3e3c22511b74"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0912.4444",
    "kind": "arxiv",
    "version": 1
  }
}