If a non-real logarithm λ and its conjugate are algebraic over one ring ℚ[x], e^{|λ|} is transcendental
ProvedDiazModulus.exp_abs_transcendental_of_isAlgebraic_adjoindiaz-modulus-leannumber-theorytranscendence
Let with algebraic and . Suppose that and are both algebraic over the ring , for some . Then
is transcendental.
The hypothesis puts and in an algebra of transcendence degree at most one, which is what four exponentials in transcendence degree one needs. With this is DiazModulus.exp_abs_transcendental_of_conj_algebraic. With and it gives DiazModulus.exp_abs_log_two_add_i_pi_transcendental.
Preamble
import Mathlib
Formal statement
open ComplexConjugate
namespace DiazModulus
theorem exp_abs_transcendental_of_isAlgebraic_adjoin (lam x : ℂ)
(hlam : IsAlgebraic ℚ (Complex.exp lam)) (him : lam.im ≠ 0)
(hl : IsAlgebraic ↥(Algebra.adjoin ℚ ({x} : Set ℂ)) lam)
(hc : IsAlgebraic ↥(Algebra.adjoin ℚ ({x} : Set ℂ)) (conj lam)) :
Transcendental ℚ (Complex.exp ((‖lam‖ : ℝ) : ℂ)) := by
sorry
end DiazModulus
Source
Known in substance: it is the argument behind G. Diaz, La conjecture des quatre exponentielles et les conjectures de D. Bertrand sur la fonction modulaire, J. Théor. Nombres Bordeaux 9 (1997), 229–245, Proposition 2, and D. Roy and M. Waldschmidt, Approximation diophantienne et indépendance algébrique de logarithmes, Ann. Sci. École Norm. Sup. (4) 30 (1997), 753–796, Corollaire 7.4. Formal proof: Diaz modulus mission, 25 September 2026 (C. Perassi).