Pith Number

pith:FGCF2INE

pith:2026:FGCF2INE43TTF7WPTO37GU45XZ

not attested not anchored not stored refs pending

Causal-Order Identification of Memoryless Sequential Quantum Processes from Restricted Projective Data

Masahito Hayashi

Necessary and sufficient conditions identify when observed data matches a memoryless sequential quantum process in one direction.

arxiv:2605.04571 v2 · 2026-05-06 · quant-ph

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\usepackage{pith}
\pithnumber{FGCF2INE43TTF7WPTO37GU45XZ}

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Record completeness

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2 Internet Archive

3 Author claim open · sign in to claim

4 Citations open

5 Replications open

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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.

Claims

C1strongest claim

We determine necessary and sufficient conditions for deciding when an observed distribution is compatible with a memoryless sequential quantum process in a fixed direction... together these conditions yield a complete criterion for membership in the memoryless sequential class.

C2weakest assumption

That the additional algebraic consistency requirement, when combined with directional conditional independence and pseudo-density matrix positivity, is both necessary and sufficient for the observed distribution to arise exactly from a memoryless sequential quantum process (rather than some other class of processes).

C3one line summary

Necessary and sufficient conditions for compatibility with memoryless sequential quantum processes combine directional conditional independence, pseudo-density matrix positivity, and a new algebraic consistency requirement.

Receipt and verification

First computed	2026-06-02T01:03:48.102594Z
Builder	pith-number-builder-2026-05-17-v1
Signature	Pith Ed25519 (`pith-v1-2026-05`) · public key
Schema	pith-number/v1.0

Canonical hash

29845d21a4e6e732fecf9bb7f3539dbe52827e5b411221f8ccea10d94a4df6e4

Aliases

arxiv: 2605.04571 · arxiv_version: 2605.04571v2 · doi: 10.48550/arxiv.2605.04571 · pith_short_12: FGCF2INE43TT · pith_short_16: FGCF2INE43TTF7WP · pith_short_8: FGCF2INE

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/FGCF2INE43TTF7WPTO37GU45XZ \
  | 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: 29845d21a4e6e732fecf9bb7f3539dbe52827e5b411221f8ccea10d94a4df6e4

Canonical record JSON

{
  "metadata": {
    "abstract_canon_sha256": "7c82b817beae24b9057fabdf9f1a86000d4dfb26b7c28b4ed969d70740abfa36",
    "cross_cats_sorted": [],
    "license": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
    "primary_cat": "quant-ph",
    "submitted_at": "2026-05-06T07:16:29Z",
    "title_canon_sha256": "047139d8d44a150e8b6c13458350ae57057a32337ca0227b939e77eb018d3400"
  },
  "schema_version": "1.0",
  "source": {
    "id": "2605.04571",
    "kind": "arxiv",
    "version": 2
  }
}