Pith Number

pith:YW45JP4Y

pith:2001:YW45JP4YHD2IQDNWRBNU7VCJXJ

not attested not anchored not stored refs pending

Cosmological Evolution of the Universe Neutral Gas Mass Measured by Quasar Absorption Systems

(2)SIRTF Science Center, California Institute of Technology, Celine Peroux (1), Lisa J. Storrie-Lombardi (2) ((1)Institute of Astronomy, Mike Irwin (1), Pasadena, Richard G. McMahon (1), UK, University of Cambridge, US)

arxiv:astro-ph/0101212 v1 · 2001-01-12 · astro-ph

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{YW45JP4YHD2IQDNWRBNU7VCJXJ}

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	2026-05-18T01:00:27.662842Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

c5b9d4bf9838f4880db6885b4fd449ba5c1b90904c22392c175fb753493ac4ae

Aliases

arxiv: astro-ph/0101212 · arxiv_version: astro-ph/0101212v1 · doi: 10.48550/arxiv.astro-ph/0101212 · pith_short_12: YW45JP4YHD2I · pith_short_16: YW45JP4YHD2IQDNW · pith_short_8: YW45JP4Y

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/YW45JP4YHD2IQDNWRBNU7VCJXJ \
  | 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: c5b9d4bf9838f4880db6885b4fd449ba5c1b90904c22392c175fb753493ac4ae

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "ae0d038fd0e12dcf9bb92aa25d2087f721651d6f1e176b52dc0b74237154c25c",
    "cross_cats_sorted": [],
    "license": "",
    "primary_cat": "astro-ph",
    "submitted_at": "2001-01-12T17:54:51Z",
    "title_canon_sha256": "b340998bc55ffcc91100cdda62ac1c4c964fb5ec33690d3c4500d5a30c4ffd48"
  },
  "schema_version": "1.0",
  "source": {
    "id": "astro-ph/0101212",
    "kind": "arxiv",
    "version": 1
  }
}