Pith Number

pith:D6DASEL7

pith:2017:D6DASEL7OYXBGEVEWPL4YVRZXP

not attested not anchored not stored refs pending

Chern's contribution to the Hopf problem: an exposition based on Bryant's paper

Aleksy Tralle, Markus Upmeier

arxiv:1708.02904 v2 · 2017-08-09 · math.DG

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{D6DASEL7OYXBGEVEWPL4YVRZXP}

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	2026-05-18T00:18:46.317676Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

1f8609117f762e1312a4b3d7cc5639bbc78ccf6a5894d402d5a5461e1b9c49ae

Aliases

arxiv: 1708.02904 · arxiv_version: 1708.02904v2 · doi: 10.48550/arxiv.1708.02904 · pith_short_12: D6DASEL7OYXB · pith_short_16: D6DASEL7OYXBGEVE · pith_short_8: D6DASEL7

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/D6DASEL7OYXBGEVEWPL4YVRZXP \
  | 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: 1f8609117f762e1312a4b3d7cc5639bbc78ccf6a5894d402d5a5461e1b9c49ae

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "3e478387f4ff1b8b66bae9300b57f34a5c4dce65e8431c6ac47d2bf318aff5ee",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.DG",
    "submitted_at": "2017-08-09T16:55:41Z",
    "title_canon_sha256": "341a534205a93db42afdab2e7df5b069ac7654040a8f46f857629b240ae15e05"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1708.02904",
    "kind": "arxiv",
    "version": 2
  }
}