Pith Number

pith:QP7XVEFR

pith:2012:QP7XVEFRFBR5I4PPKL4X4SPAJS

not attested not anchored not stored refs pending

An upper limit to the variation in the fundamental constants at redshift z = 5.2

D. Reimers, F. Boone, F. Combes, I. I. Agafonova, M. G. Kozlov, S. A. Levshakov

arxiv:1203.3649 v1 · 2012-03-16 · 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{QP7XVEFRFBR5I4PPKL4X4SPAJS}

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	2026-05-18T03:21:21.707154Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

83ff7a90b12863d471ef52f97e49e04cb84ddec460ee382f5835818e034ec3a2

Aliases

arxiv: 1203.3649 · arxiv_version: 1203.3649v1 · doi: 10.48550/arxiv.1203.3649 · pith_short_12: QP7XVEFRFBR5 · pith_short_16: QP7XVEFRFBR5I4PP · pith_short_8: QP7XVEFR

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/QP7XVEFRFBR5I4PPKL4X4SPAJS \
  | 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: 83ff7a90b12863d471ef52f97e49e04cb84ddec460ee382f5835818e034ec3a2

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "92894955112d485dcd0182ac040c6a6d2605c2968f44c3be2529b8328dea598e",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.CO",
    "submitted_at": "2012-03-16T09:46:52Z",
    "title_canon_sha256": "117fd18e6b42d65e536ee8d3b6c39faf5d681dd162dd6c0d5735c5d8710f6453"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1203.3649",
    "kind": "arxiv",
    "version": 1
  }
}