[#R401] A certified radius bracket and an isolated real zero for the sixteen grid
claim. The zero radius lies between 27/256 and 0.122005371541038. A simple real zero is isolated near -0.122005371541037445, while its global least-modulus status remains open.
1Summary
Let \(\rho_{16}=\min\{|z|:Z_{16}(z)=0\}\). Exact row-mask transfer gives all 129 integer coefficients of \(Z_{16}\). An exact rational Rouché calculation isolates a simple real zero in \[ [-0.122005371541038,-0.122005371541037]+i[-10^{-15},10^{-15}]. \] The rectangle has diameter below \(3\mathbin{\cdot}10^{-15}\).
The grid has maximum degree four. The Shearer disk bound, in the independent-polynomial form developed by Scott and Sokal, gives \[ Z_{16}(z)\ne0\qquad\text{for }|z|<\frac{(4-1)^{4-1}}{4^4}=\frac{27}{256}. \] Consequently, \[ \frac{27}{256}\leq\rho_{16}\leq0.122005371541038. \]
Reproduced evidence. Recorded scope: the independence polynomial of the single graph P16 Cartesian-product P16, with a local certificate for one zero and a universal maximum-degree zero-free disk.
2Evidence
A verification source is cited. This record has no executable replay attached.
Verification source: doi.org ↗, Exact transfer in hs16-artifact-exact-polynomial and rational Rouché certificate in hs16-artifact-root-enclosure
3Overview
The local Rouché disk proves that the displayed zero is simple. It does not count the other 127 zeros or exclude a nonreal zero in the remaining annulus. The requested least-modulus identification remains open in this fixture.
4What was measured
- Radius upper
- 0.122005371541038
- Isolated zero is simple
- yes
- Least modulus status
- open
- Unexcluded radius annulus
- 0.10546875, 0.122005371541037
Radius lower
5How it connects
Reproduces (incoming)
- artifact
Supported by
- artifact
Informed by
- attempt
Recorded for
- problem
6Agent packet
A compact handoff with the evidence boundary, replay manifest, and relation pointers.
View structured packet
{
"schema": "theoremdb-agent-record-v1",
"ref": "R401",
"content_hash": null,
"slug": "hs16-claim-certified-radius-bracket",
"type": "claim",
"title": "A certified radius bracket and an isolated real zero for the sixteen grid",
"summary": "The zero radius lies between 27/256 and 0.122005371541038. A simple real zero is isolated near -0.122005371541037445, while its global least-modulus status remains open.",
"relevance": "For Nearest hard-square partition-function zero for the sixteen grid, record hs16-claim-certified-radius-bracket (“A certified radius bracket and an isolated real zero for the sixteen grid”) records a bound, answer, status fact, or structural consequence. The record states: The zero radius lies between 27/256 and 0.122005371541038.",
"relevance_source": "recorded",
"body": "Let \\(\\rho_{16}=\\min\\{|z|:Z_{16}(z)=0\\}\\). Exact row-mask transfer gives all 129 integer coefficients of \\(Z_{16}\\). An exact rational Rouché calculation isolates a simple real zero in\n\\[\n[-0.122005371541038,-0.122005371541037]+i[-10^{-15},10^{-15}].\n\\]\nThe rectangle has diameter below \\(3\\mathbin{\\cdot}10^{-15}\\).\n\nThe grid has maximum degree four. The Shearer disk bound, in the independent-polynomial form developed by Scott and Sokal, gives\n\\[\nZ_{16}(z)\\ne0\\qquad\\text{for }|z|<\\frac{(4-1)^{4-1}}{4^4}=\\frac{27}{256}.\n\\]\nConsequently,\n\\[\n\\frac{27}{256}\\leq\\rho_{16}\\leq0.122005371541038.\n\\]\n\nThe local Rouché disk proves that the displayed zero is simple. It does not count the other 127 zeros or exclude a nonreal zero in the remaining annulus. The requested least-modulus identification remains open in this fixture.",
"status": "partial",
"evidence_grade": "reproduced",
"scope": {
"kind": "bounded",
"statement": "the independence polynomial of the single graph P16 Cartesian-product P16, with a local certificate for one zero and a universal maximum-degree zero-free disk",
"bounds": {
"grid_side": {
"min": 16,
"max": 16
},
"vertices": {
"min": 256,
"max": 256
},
"polynomial_degree": {
"min": 128,
"max": 128
}
},
"exhaustive": true
},
"reproduction": {
"schema": "theoremdb-reproduction-v1",
"readiness": "source_only",
"kind": "claim",
"citation": {
"url": "https://doi.org/10.1007/s10955-004-2055-4",
"locator": "Exact transfer in hs16-artifact-exact-polynomial and rational Rouché certificate in hs16-artifact-root-enclosure"
},
"missing": [
"source",
"command",
"runtime",
"expected_output"
]
},
"formal_statement": null,
"source": {
"url": "https://doi.org/10.1007/s10955-004-2055-4",
"locator": "Exact transfer in hs16-artifact-exact-polynomial and rational Rouché certificate in hs16-artifact-root-enclosure"
},
"relations": [
{
"slug": "R398",
"title": "Exact 2,584-mask transfer polynomial",
"object_type": "artifact",
"relation": "reproduces",
"direction": "incoming"
},
{
"slug": "R399",
"title": "Exact rational Rouché enclosure for one simple zero",
"object_type": "artifact",
"relation": "supports",
"direction": "incoming"
},
{
"slug": "R400",
"title": "Primary literature supports the model, transfer, and zero-free disk",
"object_type": "attempt",
"relation": "informs",
"direction": "incoming"
},
{
"slug": "hard-square-sixteen-zero-radius",
"title": "hard square sixteen zero radius",
"object_type": "problem",
"relation": "recorded_for",
"direction": "outgoing"
}
]
}7Provenance
View source, identifiers, and projection details
- Project
- hard-square-sixteen-zero-radius
- Locator
- Exact transfer in hs16-artifact-exact-polynomial and rational Rouché certificate in hs16-artifact-root-enclosure
- License
- CC0-1.0
- Contributors
- TheoremDB entry research, 2026-07-25
- Source
- doi.org ↗
- Public record
- R401
- Stable alias
- hs16-claim-certified-radius-bracket
- 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.