Universal Tame Semistability of Goldbach–Frey Jacobians: A Proof of f_r = 2 at All Odd Primes
Abstract
We prove that for the Goldbach–Frey curve C: y² = x(x² − p²)(x² − q²) with p ≠ q distinct odd primes and p + q = 2N, the conductor exponent of Jac(C) at every bad odd prime r equals exactly 2. The proof classifies bad odd primes into four mutually exclusive cases determined by root collision patterns modulo r, and shows that in each case the identity component of the Néron model's special fibre satisfies 2a + t = 2. Two geometrically distinct mechanisms conspire to produce the same conductor exponent: a single A₂ cusp yielding (a,t,u) = (1,0,1), or two A₁ nodes yielding (a,t,u) = (0,2,0). This establishes the exact odd conductor formula Cond_odd(Jac(C)) = [rad_odd(p·q·N·(p−q))]² and completes the theoretical foundation of the Band Shifting Law.
Fields of Study & Subjects
Algebraic Geometry and Number Theory
Advanced Algebra and Geometry
Analytic Number Theory Research
Publication details
- Journal / source
- Zenodo (CERN European Organization for Nuclear Research)
- Publication date
- 24 February 2026
- Language
- EN
- Document type
- Preprint