Pith Number

pith:7A3UBCP4

pith:2026:7A3UBCP4DYF74MHEWY3ZXKKRVZ

not attested not anchored not stored refs pending

Factored Sparse Approximate Inverse Preconditioning via Spectral Optimization

Francesco Brarda, Rui Peng Li, Tianshi Xu, Vassilis Kalantzis, Yuanzhe Xi

arxiv:2606.22742 v1 · 2026-06-22 · math.NA · cs.NA

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

Add to your LaTeX paper

\usepackage{pith}
\pithnumber{7A3UBCP4DYF74MHEWY3ZXKKRVZ}

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	2026-06-23T02:13:46.085021Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

f8374089fc1e0bfe30e4b6379ba951ae7e2775c2c922e59623fc97a6db3b19af

Aliases

arxiv: 2606.22742 · arxiv_version: 2606.22742v1 · doi: 10.48550/arxiv.2606.22742 · pith_short_12: 7A3UBCP4DYF7 · pith_short_16: 7A3UBCP4DYF74MHE · pith_short_8: 7A3UBCP4

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/7A3UBCP4DYF74MHEWY3ZXKKRVZ \
  | 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: f8374089fc1e0bfe30e4b6379ba951ae7e2775c2c922e59623fc97a6db3b19af

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "e731c88f55e620255b1b1223b80bd1f6a761b0f665e2397119dc99d22e57d616",
    "cross_cats_sorted": [
      "cs.NA"
    ],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "math.NA",
    "submitted_at": "2026-06-22T01:06:10Z",
    "title_canon_sha256": "4e060acc4029a98cd12b61b92302e558f94d5101b249852d1df76e245af5b7ce"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2606.22742",
    "kind": "arxiv",
    "version": 1
  }
}