χR(∣T3⟩⊗5) ≤ 18

T₃ orbit, qutrit.

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.

← back to the board

Verification

lean   t3_m5_stabRankP_le_eighteen in LeanProofs.T3M5StabRank, machine-checked by Lean

Implied per-copy exponent γ ≤ 0.5262 against a published 0.5000, no improvement.

Lean proof

This bound is backed by a machine-checked theorem: t3_m5_stabRankP_le_eighteen in LeanProofs.T3M5StabRank. The recorded lake build confirms it compiles.

Compute

8 runs; 0.6 CPU-hours; 0.5 h wall-clock; on Apple silicon laptop under heavy load from other jobs, 8 annealing chains per run; claude-fable-5-1, designed the sector decomposition and drove the search.

Notes

First entry for this cell; γ = log_3(18)/5 = 0.526 is above the published 1/2, so it fills the cell rather than moving the exponent. The construction is the qutrit analogue of the Qassim-Pashayan-Gosset cat state: since Z ta = t_{a+3}, the three Galois-conjugate cat states cj = sum_i ω3^{ij} t_{1+3i}^{ot 5} are the Z^{ot 5} eigensector projections of |T3⟩⊗5, each living in a 3^4-dimensional stabilizer code, and |T3⟩⊗5 = sum_j cj / 3. Each sector's rank is the stabilizer rank of a 4-qutrit carry state; the annealer found rank 6 for each (from a rank-8 start, pruned) and rank 5 failed in five runs with residuals between 0.455 and 0.494, which is not a clean plateau. Rank 5 in every sector would give χ(|T3⟩⊗5) ≤ 15 and exponent 0.493, the first value below 1/2 for this orbit, and would propagate by the contraction cj ⊗ ck → c_{j+k} to exponent 0.491 at m = 8; a rank-4 exclusion inside the 81-dimensional code is the natural companion. At m = 3 and m = 4 the sector states have rank exactly 3 (exhaustive), reproducing 9 and 9 against the board's 8 and 9, so the route gains nothing there. Now at the lean tier: t3_m5_stabRankP_le_eighteen in LeanProofs.T3M5StabRank proves stabRankP 3 |T3⟩⊗5 ≤ 18 against IsStabP 3 from this witness, the pointwise identity being decided by the kernel on integer coordinate vectors (see lean_proofs/LeanProofs/Stabilizer/Reflect.lean).

Attribution

this repository · stabrank sector-state search · Z^5 sector (qutrit cat-state) decomposition: each of the three sector projections of |T3⟩⊗5 is a 4-qutrit carry state, annealed to rank 6 on its code space and lifted; exact coefficients over Q(ω9)

Submission

JSON
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  "schema_version": "0.1",
  "orbit": "T3",
  "m": 5,
  "direction": "upper",
  "rank": 18,
  "lean": {
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    "theorem": "t3_m5_stabRankP_le_eighteen"
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    "coeffs": [
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      "exp(2*I*pi/3)/3",
      "1/3 + exp(2*I*pi/3)/3",
      "-sqrt(3)/9 - 2*sqrt(3)*exp(2*I*pi/3)/9",
      "1/3",
      "exp(2*I*pi/3)/3",
      "sqrt(3)*exp(2*I*pi/9)/9 + 2*sqrt(3)*exp(8*I*pi/9)/9",
      "-2*sqrt(3)*exp(2*I*pi/9)/9 - sqrt(3)*exp(8*I*pi/9)/9",
      "-sqrt(3)*exp(2*I*pi/9)/9 + sqrt(3)*exp(8*I*pi/9)/9",
      "-sqrt(3)*exp(8*I*pi/9)/9 + sqrt(3)*exp(2*I*pi/9)/9",
      "-sqrt(3)*exp(8*I*pi/9)/9 + sqrt(3)*exp(2*I*pi/9)/9",
      "exp(2*I*pi/9)/3",
      "-2*sqrt(3)*exp(4*I*pi/9)/9 - sqrt(3)*exp(-8*I*pi/9)/9",
      "sqrt(3)*exp(-8*I*pi/9)/9 + 2*sqrt(3)*exp(4*I*pi/9)/9",
      "sqrt(3)*exp(-8*I*pi/9)/9 + 2*sqrt(3)*exp(4*I*pi/9)/9",
      "sqrt(3)*exp(-8*I*pi/9)/9 + 2*sqrt(3)*exp(4*I*pi/9)/9",
      "-sqrt(3)*exp(4*I*pi/9)/9 - 2*sqrt(3)*exp(-8*I*pi/9)/9",
      "-exp(4*I*pi/9)/3"
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  },
  "provenance": {
    "author": "this repository",
    "reference": "stabrank sector-state search",
    "method": "Z^5 sector (qutrit cat-state) decomposition: each of the three sector projections of |T3>^5 is a 4-qutrit carry state, annealed to rank 6 on its code space and lifted; exact coefficients over Q(w9)",
    "date": "2026-09-17",
    "github": [
      "vprusso"
    ],
    "compute": {
      "cpu_hours": 0.6,
      "wall_clock_hours": 0.5,
      "runs": 8,
      "hardware": "Apple silicon laptop under heavy load from other jobs, 8 annealing chains per run",
      "llm": [
        {
          "model": "claude-fable-5-1",
          "role": "designed the sector decomposition and drove the search"
        }
      ]
    }
  },
  "notes": "First entry for this cell; gamma = log_3(18)/5 = 0.526 is above the published 1/2, so it fills the cell rather than moving the exponent. The construction is the qutrit analogue of the Qassim-Pashayan-Gosset cat state: since Z t_a = t_{a+3}, the three Galois-conjugate cat states c_j = sum_i w3^{ij} t_{1+3i}^{ot 5} are the Z^{ot 5} eigensector projections of |T3>^5, each living in a 3^4-dimensional stabilizer code, and |T3>^5 = sum_j c_j / 3. Each sector's rank is the stabilizer rank of a 4-qutrit carry state; the annealer found rank 6 for each (from a rank-8 start, pruned) and rank 5 failed in five runs with residuals between 0.455 and 0.494, which is not a clean plateau. Rank 5 in every sector would give chi(|T3>^5) <= 15 and exponent 0.493, the first value below 1/2 for this orbit, and would propagate by the contraction c_j (x) c_k -> c_{j+k} to exponent 0.491 at m = 8; a rank-4 exclusion inside the 81-dimensional code is the natural companion. At m = 3 and m = 4 the sector states have rank exactly 3 (exhaustive), reproducing 9 and 9 against the board's 8 and 9, so the route gains nothing there. Now at the lean tier: t3_m5_stabRankP_le_eighteen in LeanProofs.T3M5StabRank proves stabRankP 3 |T3>^5 <= 18 against IsStabP 3 from this witness, the pointwise identity being decided by the kernel on integer coordinate vectors (see lean_proofs/LeanProofs/Stabilizer/Reflect.lean)."
}