Pith Number

pith:CCYL4HX2

pith:2009:CCYL4HX2N7FOO3BIWPUEME7DY5

not attested not anchored not stored refs pending

The density, the cosmic microwave background, and the proton-to-electron mass ratio in a cloud at redshift 0.9

C. Henkel, J.A. Braatz, J. Ott, K.M. Menten, M.T. Murphy, N. Jethava, R.Q. Mao, S. Muller, V.V. Flambaum

arxiv:0904.3081 v1 · 2009-04-20 · astro-ph.CO

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{CCYL4HX2N7FOO3BIWPUEME7DY5}

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	2026-05-18T02:13:58.785877Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

10b0be1efa6fcae76c28b3e84613e3c76f1b325f047c173c747e6dc454648a23

Aliases

arxiv: 0904.3081 · arxiv_version: 0904.3081v1 · doi: 10.48550/arxiv.0904.3081 · pith_short_12: CCYL4HX2N7FO · pith_short_16: CCYL4HX2N7FOO3BI · pith_short_8: CCYL4HX2

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/CCYL4HX2N7FOO3BIWPUEME7DY5 \
  | 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: 10b0be1efa6fcae76c28b3e84613e3c76f1b325f047c173c747e6dc454648a23

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "bc1018bc30fd1ae574be5e6b4f2d76c303645ed3a995d45dba7db05c45858b13",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.CO",
    "submitted_at": "2009-04-20T18:20:20Z",
    "title_canon_sha256": "10a06399c47a95a09ebc547fbc2c95c0f4f4c3ccd273f2c60399ece9edde94af"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0904.3081",
    "kind": "arxiv",
    "version": 1
  }
}