{
  "experiment": "hn_spectral_database",
  "timestamp": "2026-07-04T15:01:00Z",
  "include_degrey": true,
  "graphs": [
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      "description": "Moser spindle",
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      "n_edges": 12,
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      "description": "Golomb graph (8 vertices, 10 edges)",
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      "n_edges": 10,
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      "gap": "gap=1"
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      "description": "Empty graph (10v baseline)",
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      "description": "Path graph P10 (baseline)",
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      "description": "Cycle C5 (baseline)",
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      "description": "Complete K4 (baseline)",
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      "lambda_max": 3.0,
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      "welch_wynn": 4.0,
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      "best_spectral_lower_bound": 4,
      "chi_known": 4,
      "gap": "tight"
    },
    {
      "description": "De Grey G (1581 vertices, 7877 edges)",
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      "welch_wynn": null,
      "chi_welch_wynn": null,
      "best_spectral_lower_bound": 3,
      "chi_known": 5,
      "gap": "gap=2"
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    {
      "description": "de Grey subgraph (n=50, e=100)",
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      "n_edges": 100,
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      "gap": "?"
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    {
      "description": "de Grey subgraph (n=100, e=266)",
      "n_vertices": 100,
      "n_edges": 266,
      "lambda_max": 7.080506734483,
      "lambda_min": -4.563418201316,
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      "best_spectral_lower_bound": 3,
      "chi_known": null,
      "gap": "?"
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    {
      "description": "de Grey subgraph (n=200, e=747)",
      "n_vertices": 200,
      "n_edges": 747,
      "lambda_max": 9.241919119832,
      "lambda_min": -5.218824047335,
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      "chi_welch_wynn": null,
      "best_spectral_lower_bound": 3,
      "chi_known": null,
      "gap": "?"
    },
    {
      "description": "de Grey subgraph (n=500, e=2242)",
      "n_vertices": 500,
      "n_edges": 2242,
      "lambda_max": 11.690329949761,
      "lambda_min": -7.523976221726,
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      "best_spectral_lower_bound": 3,
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      "gap": "?"
    }
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  "sha256": "2041b3ce8902f73ae8b92f1696b6badbd69718d30304c78dfa61ec67b5e270c1"
}