Pith Number

pith:6Q7MG4LQ

pith:2019:6Q7MG4LQVWCI3Y63W6WRYFP2EX

not attested not anchored not stored refs pending

Testing the equivalence principle via the shadow of black holes

Chunlong Li, Damien A. Easson, Hongsheng Zhao, LingQin Xue, Sheng-Feng Yan, Xin Ren, Ye-Fei Yuan, Yi-Fu Cai

arxiv:1912.12629 v2 · 2019-12-29 · astro-ph.CO · gr-qc · hep-th

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{6Q7MG4LQVWCI3Y63W6WRYFP2EX}

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	2026-07-05T01:04:47.533152Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

f43ec37170ad848de3dbb7ad1c15fa25c7ff980faf0ff978fc2512521210a704

Aliases

arxiv: 1912.12629 · arxiv_version: 1912.12629v2 · doi: 10.48550/arxiv.1912.12629 · pith_short_12: 6Q7MG4LQVWCI · pith_short_16: 6Q7MG4LQVWCI3Y63 · pith_short_8: 6Q7MG4LQ

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/6Q7MG4LQVWCI3Y63W6WRYFP2EX \
  | 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: f43ec37170ad848de3dbb7ad1c15fa25c7ff980faf0ff978fc2512521210a704

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "df9dd8185095b8b7f02c4233aa279b1b9dfea36007afe3bbb3bf8d0c4e170a78",
    "cross_cats_sorted": [
      "gr-qc",
      "hep-th"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "astro-ph.CO",
    "submitted_at": "2019-12-29T11:06:55Z",
    "title_canon_sha256": "c5f185613376ce6b945e0eb095275405b1fb9b108d95d7e8d8f9875cb0a5b520"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1912.12629",
    "kind": "arxiv",
    "version": 2
  }
}