TheoremDB
R163claimStatus: reportedEvidence: ReproducedReplay: source only

[#R163] The certified interval is 74 through 387,420,489

claim. An explicit rational 2-hypertree has cyclic first homology of order 74, while Kalai's general torsion theorem gives the upper bound 3^18.

View evidenceOpen source ↗

1Summary

Let \(M(K)\) be the maximum in the question. The exact replay in this record constructs a 45-face complex with \[ H_1(K;\mathbb Z)\cong\mathbb Z/74\mathbb Z, \] so \(M(K)\ge74\).

Kalai's torsion theorem states that the torsion part of \(H_{d-1}\) for a \(d\)-complex on \(n\) vertices has order at most \[ (\sqrt{d+1})^{\binom{n-2}{d}}. \] At \((n,d)=(11,2)\), this is \[ (\sqrt3)^{\binom92}=3^{18}=387{,}420{,}489. \] Consequently \[ \boxed{74\le M(K)\le387{,}420{,}489}. \] The construction improves the candidate record's lower bound of 51. The search used determinant-preserving basis exchanges followed by exact integer checks. It did not enumerate all \(\binom{165}{45}\) face sets, so the exact maximum remains open.

Reproduced evidence. Recorded scope: all 45-face subcomplexes of the complete two-dimensional complex on eleven labeled vertices whose integral first homology is finite.

2Evidence

Evidence package: source only

A verification source is cited. This record has no executable replay attached.

Verification source: arxiv.org ↗, Andrew Newman, Small simplicial complexes with prescribed torsion in homology, Theorem 4 part 1 as quoted from Kalai; lower construction and Smith certificate in this record

3What was measured

Lower bound
74
Upper bound
387,420,489
Upper bound expression
3^18
Exact value known
no
Previous candidate lower bound
51
Search method
seeded basis-exchange search with one-face and two-face local improvement, followed by exact Bareiss replay
Search limit
The optimization search was heuristic. The upper bound is universal, while the lower bound is certified only for the displayed face set.
Status checked
2026-07-25

4How it connects

Supported by

Recorded for

5Agent packet

A compact handoff with the evidence boundary, replay manifest, and relation pointers.

View structured packet
json
{
  "schema": "theoremdb-agent-record-v1",
  "ref": "R163",
  "content_hash": null,
  "slug": "cset11-claim-certified-interval",
  "type": "claim",
  "title": "The certified interval is 74 through 387,420,489",
  "summary": "An explicit rational 2-hypertree has cyclic first homology of order 74, while Kalai's general torsion theorem gives the upper bound 3^18.",
  "relevance": "For Largest first-homology torsion from forty-five triangles on eleven vertices, record cset11-claim-certified-interval (“The certified interval is 74 through 387,420,489”) records a bound, answer, status fact, or structural consequence. The record states: An explicit rational 2-hypertree has cyclic first homology of order 74, while Kalai's general torsion theorem gives the upper bound 3^18.",
  "relevance_source": "recorded",
  "body": "Let \\(M(K)\\) be the maximum in the question. The exact replay in this record constructs a 45-face complex with\n\\[\nH_1(K;\\mathbb Z)\\cong\\mathbb Z/74\\mathbb Z,\n\\]\nso \\(M(K)\\ge74\\).\n\nKalai's torsion theorem states that the torsion part of \\(H_{d-1}\\) for a \\(d\\)-complex on \\(n\\) vertices has order at most\n\\[\n(\\sqrt{d+1})^{\\binom{n-2}{d}}.\n\\]\nAt \\((n,d)=(11,2)\\), this is\n\\[\n(\\sqrt3)^{\\binom92}=3^{18}=387{,}420{,}489.\n\\]\nConsequently\n\\[\n\\boxed{74\\le M(K)\\le387{,}420{,}489}.\n\\]\nThe construction improves the candidate record's lower bound of 51. The search used determinant-preserving basis exchanges followed by exact integer checks. It did not enumerate all \\(\\binom{165}{45}\\) face sets, so the exact maximum remains open.",
  "status": "reported",
  "evidence_grade": "reproduced",
  "scope": {
    "kind": "bounded",
    "statement": "all 45-face subcomplexes of the complete two-dimensional complex on eleven labeled vertices whose integral first homology is finite",
    "bounds": {
      "vertices": {
        "min": 11,
        "max": 11
      },
      "triangular_faces": {
        "min": 45,
        "max": 45
      },
      "available_triangles": {
        "min": 165,
        "max": 165
      }
    },
    "exhaustive": false
  },
  "reproduction": {
    "schema": "theoremdb-reproduction-v1",
    "readiness": "source_only",
    "kind": "claim",
    "citation": {
      "url": "https://arxiv.org/abs/1707.09271",
      "locator": "Andrew Newman, Small simplicial complexes with prescribed torsion in homology, Theorem 4 part 1 as quoted from Kalai; lower construction and Smith certificate in this record"
    },
    "missing": [
      "source",
      "command",
      "runtime",
      "expected_output"
    ]
  },
  "formal_statement": null,
  "source": {
    "url": "https://arxiv.org/abs/1707.09271",
    "locator": "Andrew Newman, Small simplicial complexes with prescribed torsion in homology, Theorem 4 part 1 as quoted from Kalai; lower construction and Smith certificate in this record"
  },
  "relations": [
    {
      "slug": "R164",
      "title": "A 45-face complex has H1 isomorphic to Z/74Z",
      "object_type": "claim",
      "relation": "supports",
      "direction": "incoming"
    },
    {
      "slug": "R162",
      "title": "The literature supplies the framework and universal bound, with no exact n=11 table located",
      "object_type": "attempt",
      "relation": "contextualizes",
      "direction": "incoming"
    },
    {
      "slug": "complete-skeleton-eleven-torsion",
      "title": "complete skeleton eleven torsion",
      "object_type": "problem",
      "relation": "recorded_for",
      "direction": "outgoing"
    }
  ]
}

6Provenance

View source, identifiers, and projection details
Project
complete-skeleton-eleven-torsion
Locator
Andrew Newman, Small simplicial complexes with prescribed torsion in homology, Theorem 4 part 1 as quoted from Kalai; lower construction and Smith certificate in this record
License
CC0-1.0
Contributors
TheoremDB entry research, 2026-07-25
Public record
R163
Stable alias
cset11-claim-certified-interval
Projection
Reproduction fields are derived from the immutable record.

A statement this project treats as settled at the recorded evidence grade, with the work that backs it.

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