Pith Number record

pith:X37TDJUW

pith:2018:X37TDJUWWIYSUEPBPRJS2QZTTV

Protocol content-addressed Pith receipt schema 1.0

Author: not author-attested
Timestamp: not externally anchored
Storage: storage not verified
References: references not resolved

Constraining the mass density of free-floating black holes using razor-thin lensing arcs

Anupreeta More, Frank C. van den Bosch, Giulia Despali, John P. McKean, Michael Tremmel, Simona Vegetti, Surhud More, Uddipan Banik

Source: arxiv:1811.00637 v2 · Submitted 2018-11-01 · License http://arxiv.org/licenses/nonexclusive-distrib/1.0/

Categories: astro-ph.CO · astro-ph.GA

Open Pith paper page Download JSON What is a Pith Number?

Record completeness checklist

Each row is a typed event attached to this Pith Number. Done rows show their third-party proof. Open rows have an inline form so you can complete them without leaving this page.

1 Anchor canonical hash to Bitcoin via OpenTimestamps open

Stamps the canonical SHA-256 (beff31a696b2312a11e17c53...) across three calendars. Confirms instantly. Calendars upgrade to a Bitcoin-block proof in a few hours.

2 Mirror to Internet Archive (Wayback Machine) open

Submits the paper URL to the Internet Archive and records the resulting Wayback capture URL plus timestamp. Pith does not host the paper.

3 Claim authorship open

Identity-backed. The same flow as the paper page. Sign in with ORCID, Apple, X, or email magic-link; if your ORCID is on the arXiv author list the attestation is one-click and shows ORCID verified.

4 Sign a citation pointing at this record open

Records a signed citation. Pick a relationship (supports, refutes, extends, uses_method, depends_on, replaces, compares, cites). Pith signs the assertion server-side.

Relationship

Citing URL (e.g. arxiv.org/abs/...)

More options

Target claim ID (e.g. C1)

Citing Pith Number (pith:YYYY:...)

Note (public, max 500 chars)

Your name

Email (not displayed)

ORCID

Held for moderation. Sign in to confirm immediately.

5 Submit replication, falsification, or formal bridge open

Public record of a replication attempt, formal bridge (Lean / Coq), or falsification. Held for moderation. Not peer review; a typed annotation.

Result class

Evidence URL (http(s))

More options

Target claim ID (e.g. C1) Methodology (public, max 1500 chars) Summary (public, max 1500 chars)

Your name

Email (not displayed)

ORCID

Held for moderation before it appears as confirmed.

Claims

Receipt

First computed	2026-05-17T23:57:56.914424Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`, fingerprint `8d4b5ee74e4693bc…`) · public key
Signature value	`kebuLslKJ03TPgPLdHEEOX5kF5/+urATzfF01b864HLCtenrBxbpfv/R1wYUtSw/yAZy33wDdppg/0YupNw9Cg==`
Schema	pith-number/v1.0

Canonical hash

beff31a696b2312a11e17c532d43339d7682abefb9d9188a592774bc91dab837

Aliases

Kind	Value
arxiv	`1811.00637`
arxiv_version	`1811.00637v2`
doi	`10.48550/arxiv.1811.00637`

Agent API

Same address serves humans and agents. Add an Accept header to get the JSON-LD payload at the resolver URL itself.

Resolver JSON Graph JSON Events JSON Schema Signing key Resolve alias

Verify this Pith Number yourself

Three shell lines recompute the canonical hash. If the hash you compute matches the one shown above, the record is intact end-to-end.

curl -sH 'Accept: application/ld+json' https://pith.science/pith/X37TDJUWWIYSUEPBPRJS2QZTTV \
  | 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: beff31a696b2312a11e17c532d43339d7682abefb9d9188a592774bc91dab837

Verify the Pith Ed25519 signature against the published public key:

curl -s https://pith.science/pith-signing-key.json | jq -r .public_key_b64 \
  | base64 -d > /tmp/pith_pub.bin
python3 -c "
from cryptography.hazmat.primitives.asymmetric.ed25519 import Ed25519PublicKey
import base64
pub = Ed25519PublicKey.from_public_bytes(open('/tmp/pith_pub.bin','rb').read())
sig = base64.b64decode('kebuLslKJ03TPgPLdHEEOX5kF5/+urATzfF01b864HLCtenrBxbpfv/R1wYUtSw/yAZy33wDdppg/0YupNw9Cg==')
digest = bytes.fromhex('beff31a696b2312a11e17c532d43339d7682abefb9d9188a592774bc91dab837')
pub.verify(sig, digest)
print('signature OK')"

Show canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "107b7b03a2989a64b292c854312a0be2bdf24b0ac457c7af7852a58012e97408",
    "cross_cats_sorted": [
      "astro-ph.GA"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.CO",
    "submitted_at": "2018-11-01T21:15:21Z",
    "title_canon_sha256": "1d26cf91502bcd52756a1b756c3296cc463c108682d29d0f0cf7fe7ba779313f"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1811.00637",
    "kind": "arxiv",
    "version": 2
  }
}