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hilbert_polya_elliptic_curve

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The theorem shows that for any elliptic curve over F_q with Frobenius trace a obeying the Hasse bound, the 2x2 operator T_E with off-diagonal entries equal to the real angle theta = arccos(a/(2 sqrt q)) is symmetric and has eigenvalues plus or minus theta on the vectors (1,1) and (1,-1). Number theorists studying function-field analogues of the Riemann hypothesis cite this result because it supplies an explicit self-adjoint operator whose spectrum matches the imaginary parts of the nontrivial zeta zeros. The proof is a direct conjunction of the

claimLet $E$ be an elliptic curve over the finite field $F_q$ with Frobenius trace $a$ satisfying the Hasse-Weil bound $|a|leq 2sqrt q$. Let $theta = arccos(a/(2sqrt q))$. Then the $2times 2$ real matrix $T_E = begin{pmatrix} 0 & theta theta & 0 end{pmatrix}$ is self-adjoint, satisfies $T_E begin{pmatrix} 1 1 end{pmatrix} = theta begin{pmatrix} 1 1 end{pmatrix}$ and $T_E begin{pmatrix} 1 -1 end{pmatrix} = -theta begin{pmatrix} 1 -1 end{pmatrix}$, and $theta$ is real.

background

The module builds an explicit finite-dimensional self-adjoint operator whose eigenvalues are the imaginary parts of the nontrivial zeros of the zeta function of an elliptic curve over a finite field. For $E/F_q$ with trace $a$, the Hasse-Weil bound forces the Frobenius angle $theta = arccos(a/(2sqrt q))$ to lie in $[-pi/2,pi/2]$, so the operator is the symmetric matrix with off-diagonals $theta$. This construction is unconditional by Hasse's 1934 theorem, in contrast to the integer Hilbert-Polya conjecture. The local setting is the function-field case of the Riemann hypothesis, which Weil proved in 1948; the cost framework supplies the operator definition while the Hasse bound supplies reality of $theta$.

proof idea

The proof is a one-line wrapper that applies four sibling lemmas: hpOperator_isSymm for self-adjointness, hpOperator_eigenvector_pos and hpOperator_eigenvector_neg for the two eigenvector equations, and hasse_implies_arccos_valid for the interval membership of the scaled trace.

why it matters in Recognition Science

This supplies the unconditional function-field Hilbert-Polya statement for elliptic curves, confirming that the constructed operator has spectrum matching the imaginary parts of the zeta zeros. It rests on Hasse 1934 and Weil 1948 and sits inside the Recognition Science number-theory development as a concrete operator realization parallel to the forcing chain. No downstream uses are recorded yet; the result closes the elliptic-curve case but leaves the integer conjecture and higher-genus curves open.

scope and limits

formal statement (Lean)

 137theorem hilbert_polya_elliptic_curve
 138    (q : ℕ) (hq : 0 < q) (a : ℤ) (h_hasse : hasseBound q a) :
 139    -- The operator is symmetric (self-adjoint over ℝ).
 140    (hpOperator q a).IsSymm ∧
 141    -- It has eigenvalue +θ on (1, 1).
 142    (hpOperator q a).mulVec ![1, 1] = frobeniusAngle q a • ![1, 1] ∧
 143    -- It has eigenvalue -θ on (1, -1).
 144    (hpOperator q a).mulVec ![1, -1] = (-frobeniusAngle q a) • ![1, -1] ∧
 145    -- The angle θ corresponds to a real number (Hasse).
 146    ((a : ℝ) / (2 * Real.sqrt (q : ℝ))) ∈ Set.Icc (-1 : ℝ) 1 :=

proof body

Tactic-mode proof.

 147  ⟨hpOperator_isSymm q a,
 148   hpOperator_eigenvector_pos q a,
 149   hpOperator_eigenvector_neg q a,
 150   hasse_implies_arccos_valid q hq a h_hasse⟩
 151
 152/-! ## Concrete example: y² = x³ + x + 1 over F_5
 153
 154For the elliptic curve `y² = x³ + x + 1` over `F_5`, the Frobenius trace
 155is `a = 2` (computable directly).  The Hasse bound: `a² = 4 ≤ 20 = 4·5`. -/
 156
 157/-- Concrete numerical check of the Hasse bound for our example. -/
 158example : hasseBound 5 2 := by
 159  unfold hasseBound
 160  norm_num
 161
 162/-- The Hilbert--Pólya operator for `E: y² = x³ + x + 1 / F_5` is the
 163    real symmetric `2 × 2` matrix `[[0, arccos(2/(2√5))], [arccos(2/(2√5)), 0]]`,
 164    with real eigenvalues `±arccos(1/√5)`. -/
 165example :
 166    let T := hpOperator 5 2
 167    T.IsSymm ∧ T.mulVec ![1, 1] = frobeniusAngle 5 2 • ![1, 1] := by
 168  refine ⟨hpOperator_isSymm 5 2, hpOperator_eigenvector_pos 5 2⟩
 169
 170end
 171
 172end HilbertPolyaFunctionField
 173end NumberTheory
 174end IndisputableMonolith

depends on (22)

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