[#R383] A mod-two vanishing table does not prove integral 6-connectivity
1Summary
The 2026 cohomology paper infers 6-connectivity from mod-two homology vanishing through degree 6. That coefficient calculation leaves odd-primary integral torsion possible, so the inference needs another argument.
The source audit checked arXiv:2605.00705v2, revised 2026-07-17. Its introduction says that Ripser calculated the first 15 homology groups of \(\operatorname{VR}(Q_6;4)\) with \(\mathbb Z/2\) coefficients, found the first nonzero group in degree 7, and thereby showed 6-connectivity. Page 5 repeats exact 6-connectivity and states \(H_7(-;\mathbb Z)\ne0\).
Vanishing over \(\mathbb F_2\) in degrees 1 through 6 excludes free summands and 2-primary torsion in the corresponding universal-coefficient range. It permits odd-primary torsion. Homological vanishing over one field also supplies no direct vanishing of the homotopy groups needed for connectivity. The paper's rigorous total-domination bound gives only 3-connectivity, while the exact invariant in this packet improves that route to 4-connectivity.
Supported evidence. Recorded scope: the coefficient logic used for the claimed 6-connectivity of VR(Q_6;4) in arXiv:2605.00705v2.
2Outcome
A verification source is cited. This record has no executable replay attached.
Verification source: arxiv.org ↗, Introduction page 2, Theorem 2.3, Theorem 2.6, and discussion on page 5
3Overview
The audit located no additional proof in the paper that closes the coefficient gap. This is a source-scope advisory about the connectivity sentence. It does not affect the canonical torsion question's definition.
4What was measured
- Audit date
- 2026-07-28
- Source revision
- arXiv:2605.00705v2
- Source revision date
- 2026-07-17
- Audit environment
- complete PDF text extraction followed by manual review of the introduction, Theorems 2.3 and 2.6, and the n=6 discussion
- Stopping rule
- trace every cited justification for the n=6 connectivity sentence and stop after checking the complete current revision and all torsion-text matches
- Retry condition
- repeat when the source receives a new revision or an additional integral-connectivity argument is cited
- Coefficient in computation
- F_2
- Claimed connectivity
- 6
- Rigorous total domination connectivity in source
- 3
- Exact total domination connectivity in this packet
- 4
- Torsion text search matches
- 0
- Advisory
- The mod-two calculation alone does not exclude odd-primary homology.
5How it connects
Informs
- claim
Recorded for
- problem
6Agent packet
A compact handoff with the evidence boundary, replay manifest, and relation pointers.
View structured packet
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"ref": "R383",
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"slug": "hr4-attempt-coefficient-connectivity-audit",
"type": "attempt",
"title": "A mod-two vanishing table does not prove integral 6-connectivity",
"summary": "The 2026 cohomology paper infers 6-connectivity from mod-two homology vanishing through degree 6. That coefficient calculation leaves odd-primary integral torsion possible, so the inference needs another argument.",
"relevance": "For Integral torsion in scale-four hypercube Rips complexes, record hr4-attempt-coefficient-connectivity-audit (“A mod-two vanishing table does not prove integral 6-connectivity”) documents a concrete method, search boundary, or failed route. The record states: The 2026 cohomology paper infers 6-connectivity from mod-two homology vanishing through degree 6.",
"relevance_source": "recorded",
"body": "The source audit checked arXiv:2605.00705v2, revised 2026-07-17. Its introduction says that Ripser calculated the first 15 homology groups of \\(\\operatorname{VR}(Q_6;4)\\) with \\(\\mathbb Z/2\\) coefficients, found the first nonzero group in degree 7, and thereby showed 6-connectivity. Page 5 repeats exact 6-connectivity and states \\(H_7(-;\\mathbb Z)\\ne0\\).\n\nVanishing over \\(\\mathbb F_2\\) in degrees 1 through 6 excludes free summands and 2-primary torsion in the corresponding universal-coefficient range. It permits odd-primary torsion. Homological vanishing over one field also supplies no direct vanishing of the homotopy groups needed for connectivity. The paper's rigorous total-domination bound gives only 3-connectivity, while the exact invariant in this packet improves that route to 4-connectivity.\n\nThe audit located no additional proof in the paper that closes the coefficient gap. This is a source-scope advisory about the connectivity sentence. It does not affect the canonical torsion question's definition.",
"status": "completed",
"evidence_grade": "sourced",
"scope": {
"kind": "bounded",
"statement": "the coefficient logic used for the claimed 6-connectivity of VR(Q_6;4) in arXiv:2605.00705v2",
"bounds": {
"cube_dimension": {
"min": 6,
"max": 6
},
"scale": {
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"vanishing_degree": {
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"max": 6
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"exhaustive": false
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"citation": {
"url": "https://arxiv.org/abs/2605.00705",
"locator": "Introduction page 2, Theorem 2.3, Theorem 2.6, and discussion on page 5"
},
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"source": {
"url": "https://arxiv.org/abs/2605.00705",
"locator": "Introduction page 2, Theorem 2.3, Theorem 2.6, and discussion on page 5"
},
"relations": [
{
"slug": "R388",
"title": "Torsion-free through n=5 and no 2-primary torsion at n=6",
"object_type": "claim",
"relation": "informs",
"direction": "outgoing"
},
{
"slug": "hypercube-rips-scale-four-torsion-free",
"title": "hypercube rips scale four torsion free",
"object_type": "problem",
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]
}7Provenance
View source, identifiers, and projection details
- Project
- hypercube-rips-scale-four-torsion-free-research
- Locator
- Introduction page 2, Theorem 2.3, Theorem 2.6, and discussion on page 5
- License
- CC0-1.0
- Contributors
- Martin Bendersky, Salvatore Elia, Jelena Grbić
- Source
- arxiv.org ↗
- Public record
- R383
- Stable alias
- hr4-attempt-coefficient-connectivity-audit
- Projection
- Reproduction fields are derived from the immutable record.
A route someone took, recorded so the next person can reuse it or avoid it.