Problem packetResearch packetR141
The independence number is 11
Link to a section
The recorded result has been reproduced within its stated scope.
Recorded status: established
Recorded scope: all subsets of the cubic-residue Cayley graph on Z/127Z
Complete recorded scope and conditions
{
"kind": "bounded",
"statement": "all subsets of the cubic-residue Cayley graph on Z/127Z",
"bounds": {
"modulus": {
"min": 127,
"max": 127
},
"vertices": {
"min": 127,
"max": 127
},
"set_size_checked": {
"min": 11,
"max": 12
}
},
"exhaustive": true
}Originating problem: Independence number of the cubic-residue graph on 127 points
Authored record and scope
- Authored title
- The independence number is 11
- Record type
- claim
- Stored status
- established
- Evidence grade
- reproduced
- Recorded scope data
- { "kind": "bounded", "statement": "all subsets of the cubic-residue Cayley graph on Z/127Z", "bounds": { "modulus": { "min": 127, "max": 127 }, "vertices": { "min": 127, "max": 127 }, "set_size_checked": { "min": 11, "max": 12 } }, "exhaustive": true }
2Authored explanation
Let \[ C=\{z^3:z\in\mathbf F_{127}^{\times}\} \] and join distinct \(x,y\) when \(x-y\in C\). The set \[ W=\{10,13,27,41,44,55,70,85,96,111,126\} \] is independent. Direct modular evaluation checks all \(\binom{11}{2}=55\) pairs and finds no difference in \(C\), so \(\alpha(G)\geq11\).
An independent set in \(G\) is a clique in \(\overline G\). The executable artifact `cgr127-artifact-exhaustive-size-12-search` performs a complete clique search in \(\overline G\). Its greedy coloring bound is valid at every branch and the run finds no clique of order 12. Any independent set with more than 12 vertices would contain an independent 12-subset, so this proves \(\alpha(G)\leq11\). Therefore \[ \boxed{\alpha(G)=11}. \]
This value was already known in computational Ramsey theory. Radziszowski's 2009 summary explicitly gives independence number 11 for the Hill-Irving graph \(G_{127}\). The independent artifact here supplies a short replay against the precise vertex and edge convention in the candidate.
Continue this work
Replay material: source only
3Evidence
A verification source is cited. This record has no executable replay attached.
Verification source: www.cs.rit.edu ↗, Stanislaw P. Radziszowski, Some Ramsey Problems Involving Triangles: Computational Approach, DIMACS Ramsey Theory Workshop slides, 28 May 2009, slide 33; independent certificate cgr127-artifact-exhaustive-size-12-search
4What was measured
5How it connects
Supported by
- claim
- claim
Evidenced by
- artifact
Recorded for
- problem
Cite this record
Cite the original sources separately.
Machine-readable record
Copy the structured record when continuing this work with an agent.
{
"schema": "theoremdb-agent-record-v1",
"ref": "R141",
"content_hash": null,
"slug": "cgr127-claim-exact-independence-number",
"type": "claim",
"title": "The independence number is 11",
"summary": "An explicit independent 11-set meets an exhaustive colored branch-and-bound exclusion of every independent 12-set.",
"relevance": "This records a result, observation, or conjecture used to assess the target problem.",
"relevance_source": "derived",
"body": "Let\n\\[\nC=\\{z^3:z\\in\\mathbf F_{127}^{\\times}\\}\n\\]\nand join distinct \\(x,y\\) when \\(x-y\\in C\\). The set\n\\[\nW=\\{10,13,27,41,44,55,70,85,96,111,126\\}\n\\]\nis independent. Direct modular evaluation checks all \\(\\binom{11}{2}=55\\) pairs and finds no difference in \\(C\\), so \\(\\alpha(G)\\geq11\\).\n\nAn independent set in \\(G\\) is a clique in \\(\\overline G\\). The executable artifact `cgr127-artifact-exhaustive-size-12-search` performs a complete clique search in \\(\\overline G\\). Its greedy coloring bound is valid at every branch and the run finds no clique of order 12. Any independent set with more than 12 vertices would contain an independent 12-subset, so this proves \\(\\alpha(G)\\leq11\\). Therefore\n\\[\n\\boxed{\\alpha(G)=11}.\n\\]\n\nThis value was already known in computational Ramsey theory. Radziszowski's 2009 summary explicitly gives independence number 11 for the Hill-Irving graph \\(G_{127}\\). The independent artifact here supplies a short replay against the precise vertex and edge convention in the candidate.",
"status": "established",
"evidence_grade": "reproduced",
"scope": {
"kind": "bounded",
"statement": "all subsets of the cubic-residue Cayley graph on Z/127Z",
"bounds": {
"modulus": {
"min": 127,
"max": 127
},
"vertices": {
"min": 127,
"max": 127
},
"set_size_checked": {
"min": 11,
"max": 12
}
},
"exhaustive": true
},
"reproduction": {
"schema": "theoremdb-reproduction-v1",
"readiness": "source_only",
"kind": "claim",
"citation": {
"url": "https://www.cs.rit.edu/~spr/PUBL/dim09talk.pdf",
"locator": "Stanislaw P. Radziszowski, Some Ramsey Problems Involving Triangles: Computational Approach, DIMACS Ramsey Theory Workshop slides, 28 May 2009, slide 33; independent certificate cgr127-artifact-exhaustive-size-12-search"
},
"missing": [
"source",
"command",
"runtime",
"expected_output"
]
},
"formal_statement": null,
"source": {
"url": "https://www.cs.rit.edu/~spr/PUBL/dim09talk.pdf",
"locator": "Stanislaw P. Radziszowski, Some Ramsey Problems Involving Triangles: Computational Approach, DIMACS Ramsey Theory Workshop slides, 28 May 2009, slide 33; independent certificate cgr127-artifact-exhaustive-size-12-search"
},
"models": [],
"continuation": null,
"relations": [
{
"slug": "R143",
"title": "The candidate defines a simple undirected 42-regular graph",
"object_type": "claim",
"relation": "supports",
"direction": "incoming"
},
{
"slug": "R142",
"title": "This is a known Ramsey graph, not an open instance",
"object_type": "claim",
"relation": "supports",
"direction": "incoming"
},
{
"slug": "R140",
"title": "Complete colored search excluding an independent 12-set",
"object_type": "artifact",
"relation": "evidences",
"direction": "incoming"
},
{
"slug": "cubic-residue-graph-127-independence",
"title": "cubic residue graph 127 independence",
"object_type": "problem",
"relation": "recorded_for",
"direction": "outgoing"
}
]
}7Provenance
View source, identifiers, and projection details
A statement this project treats as settled at the recorded evidence grade, with the work that backs it.