Pith Number

pith:HA6SNJOL

pith:2009:HA6SNJOLFUUN52RHPYBSJAERWM

not attested not anchored not stored refs pending

An Observational Determination of the Proton to Electron Mass Ratio in the Early Universe

Carlos Martins, Daniel Eisenstein, Jill Bechtold, John H. Black, J. Xavier Prochaska, Robert C. Kennicutt, Rodger I. Thompson, Xiaohui Fan, Yancey L. Shirley

arxiv:0907.4392 v1 · 2009-07-24 · 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{HA6SNJOLFUUN52RHPYBSJAERWM}

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	2026-05-18T02:12:53.678977Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

383d26a5cb2d28deea277e03248091b339ab23b1980bc4d8a21848cbf9d8a8ac

Aliases

arxiv: 0907.4392 · arxiv_version: 0907.4392v1 · doi: 10.48550/arxiv.0907.4392 · pith_short_12: HA6SNJOLFUUN · pith_short_16: HA6SNJOLFUUN52RH · pith_short_8: HA6SNJOL

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/HA6SNJOLFUUN52RHPYBSJAERWM \
  | 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: 383d26a5cb2d28deea277e03248091b339ab23b1980bc4d8a21848cbf9d8a8ac

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "58ef416c8b12d53f6313420e0562ba75e5f95fc40ae4906a0e70791c9278f0c2",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.CO",
    "submitted_at": "2009-07-24T22:56:17Z",
    "title_canon_sha256": "81acba1f0bc11c93f8017686dd024bd28e8f034e13da59e2c6b77442a5062edf"
  },
  "schema_version": "1.0",
  "source": {
    "id": "0907.4392",
    "kind": "arxiv",
    "version": 1
  }
}