Pith Number

pith:7OPKYR3V

pith:2011:7OPKYR3VPG7PIVHQD4EPBBUGYP

not attested not anchored not stored refs pending

Optimal regularity for the no-sign obstacle problem

Erik Lindgren, Henrik Shahgholian, John Andersson

arxiv:1105.0717 v1 · 2011-05-04 · math.AP

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{7OPKYR3VPG7PIVHQD4EPBBUGYP}

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	2026-05-18T04:23:01.960821Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

fb9eac477579bef454f01f08f08686c3d61668df4beb27a67923b9de9baacb58

Aliases

arxiv: 1105.0717 · arxiv_version: 1105.0717v1 · doi: 10.48550/arxiv.1105.0717 · pith_short_12: 7OPKYR3VPG7P · pith_short_16: 7OPKYR3VPG7PIVHQ · pith_short_8: 7OPKYR3V

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/7OPKYR3VPG7PIVHQD4EPBBUGYP \
  | 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: fb9eac477579bef454f01f08f08686c3d61668df4beb27a67923b9de9baacb58

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "6afe64b0118f8ca5d82900e55172af61722ebcad4e06610ca0900ff41184dbb2",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.AP",
    "submitted_at": "2011-05-04T01:25:40Z",
    "title_canon_sha256": "fa977a5c5987f8ccee4d3bff1e707cd4d52373c2c0c553da129f7f9bba688032"
  },
  "schema_version": "1.0",
  "source": {
    "id": "1105.0717",
    "kind": "arxiv",
    "version": 1
  }
}