χR(∣T5⟩⊗2) ≤ 8

Tâ‚… orbit, ququint.

Participate

Run it yourself, or point a coding agent at it.

git clone https://github.com/unitaryfoundation/stabrank
cd stabrank
# describe your decomposition in bounds/mybound.json
make fit BOUND=bounds/mybound.json ARGS=--write
make verify BOUND=bounds/mybound.json

fit solves for the exact coefficients, or tells you no exact combination of your terms reproduces the target. verify rebuilds the identity in exact arithmetic. If it passes, open a pull request adding the file and the leaderboard picks it up on the next build.

A bound the pipeline cannot check is recorded as cited and never takes a record.

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Verification

lean   t5_m2_stabRankP_le_eight in LeanProofs.T5M2StabRank, machine-checked by Lean

Implied per-copy exponent γ ≤ 0.6460 against a baseline 0.6826 (single-copy product bound; no published exponent), an improvement.

Lean proof

This bound is backed by a machine-checked theorem: t5_m2_stabRankP_le_eight in LeanProofs.T5M2StabRank. The recorded lake build confirms it compiles.

Compute

2 runs; 0.1513 CPU-hours; 0.0479 h wall-clock; on arm64 Darwin, 18 cores.

Notes

Found by autoresearch/run.py on seed 7002 after 0 failed seed(s) at this rank (residuals none); the exact coefficients were recovered by fit_coeffs.fit and the identity is checked symbolically by the verifier. Implied γ log_5(8)/2 = 0.6460, below the single-copy product bound log_5(3) = 0.6826 that is the orbit's baseline (no exponent has been published for any p = 5 state). Puts the cell at 5 ≤ χ(|T5⟩⊗2) ≤ 8 with the rank-4 exclusion of cert_t5_m2_rank4.py, against the product bound 9 from χ(|T5⟩) = 3. Short annealer probes at ranks 4 to 7 plateaued at residuals 0.385, 0.311, 0.31 to 0.32 and 0.227, so ranks 5 to 7 are open. Every run is logged in autoresearch/runs.jsonl.

Attribution

this repository · stabrank autoresearch/run.py · simulated annealing at rank 8 (4 chains, 8000 iterations per temperature, cooling 0.995), then exact refit

Submission

JSON
{
  "schema_version": "0.1",
  "orbit": "T5",
  "m": 2,
  "direction": "upper",
  "rank": 8,
  "witness": {
    "terms": [
      {
        "k": 0,
        "x0": [
          4,
          3
        ],
        "W": [],
        "Q": [],
        "l": []
      },
      {
        "k": 1,
        "x0": [
          0,
          3
        ],
        "W": [
          [
            1,
            0
          ]
        ],
        "Q": [
          [
            3
          ]
        ],
        "l": [
          3
        ]
      },
      {
        "k": 1,
        "x0": [
          0,
          4
        ],
        "W": [
          [
            1,
            0
          ]
        ],
        "Q": [
          [
            0
          ]
        ],
        "l": [
          1
        ]
      },
      {
        "k": 0,
        "x0": [
          2,
          4
        ],
        "W": [],
        "Q": [],
        "l": []
      },
      {
        "k": 0,
        "x0": [
          3,
          1
        ],
        "W": [],
        "Q": [],
        "l": []
      },
      {
        "k": 1,
        "x0": [
          3,
          0
        ],
        "W": [
          [
            0,
            1
          ]
        ],
        "Q": [
          [
            0
          ]
        ],
        "l": [
          4
        ]
      },
      {
        "k": 2,
        "x0": [
          0,
          0
        ],
        "W": [
          [
            1,
            0
          ],
          [
            0,
            1
          ]
        ],
        "Q": [
          [
            3,
            0
          ],
          [
            0,
            3
          ]
        ],
        "l": [
          3,
          3
        ]
      },
      {
        "k": 1,
        "x0": [
          4,
          0
        ],
        "W": [
          [
            0,
            1
          ]
        ],
        "Q": [
          [
            3
          ]
        ],
        "l": [
          3
        ]
      }
    ],
    "coeffs": [
      "-1/4 + 3*sqrt(5)/20 + I*sqrt(1/8 - sqrt(5)/40)",
      "-1/2 - I*sqrt(1/4 - sqrt(5)/10)",
      "-sqrt(5)/4 + 1/4 - I*sqrt(sqrt(5)/40 + 1/8)",
      "-sqrt(5)/10 + I*sqrt(1/4 - sqrt(5)/10)",
      "-sqrt(5)/20 + 1/4 - I*sqrt(sqrt(5)/40 + 1/8)",
      "-1/2 - I*sqrt(1/4 - sqrt(5)/10)",
      "1",
      "-sqrt(5)/4 + 1/4 - I*sqrt(sqrt(5)/40 + 1/8)"
    ]
  },
  "provenance": {
    "author": "this repository",
    "reference": "stabrank autoresearch/run.py",
    "method": "simulated annealing at rank 8 (4 chains, 8000 iterations per temperature, cooling 0.995), then exact refit",
    "date": "2026-09-21",
    "github": [
      "vprusso"
    ],
    "compute": {
      "cpu_hours": 0.1513,
      "wall_clock_hours": 0.0479,
      "runs": 2,
      "hardware": "arm64 Darwin, 18 cores"
    }
  },
  "notes": "Found by autoresearch/run.py on seed 7002 after 0 failed seed(s) at this rank (residuals none); the exact coefficients were recovered by fit_coeffs.fit and the identity is checked symbolically by the verifier. Implied gamma log_5(8)/2 = 0.6460, below the single-copy product bound log_5(3) = 0.6826 that is the orbit's baseline (no exponent has been published for any p = 5 state). Puts the cell at 5 <= chi(|T5>^2) <= 8 with the rank-4 exclusion of cert_t5_m2_rank4.py, against the product bound 9 from chi(|T5>) = 3. Short annealer probes at ranks 4 to 7 plateaued at residuals 0.385, 0.311, 0.31 to 0.32 and 0.227, so ranks 5 to 7 are open. Every run is logged in autoresearch/runs.jsonl.",
  "lean": {
    "module": "LeanProofs.T5M2StabRank",
    "theorem": "t5_m2_stabRankP_le_eight"
  }
}