No zeros of with above height
Openzeta_ne_zero_of_strip_of_two_lt_abs_imLet denote the Riemann zeta function. The assertion is that has no zero strictly to the right of the critical line inside the critical strip, at height larger than :
This is open: it is the Riemann hypothesis with the two parts that are unconditionally known removed. Indeed, non-vanishing for is classical (Mathlib's riemannZeta_ne_zero_of_one_le_re), and non-vanishing in the low-lying rectangle , is an explicit estimate on the completed zeta function. Together with those two facts, the statement above is equivalent to the half-plane form of the Riemann hypothesis, , and hence to the Riemann hypothesis itself.
Phrasing the remaining open problem this way isolates exactly the region where the difficulty lies: a bounded-real-part, unbounded-height region on one side of the critical line. Any progress of zero-density or zero-free-region type applies to it directly.
Formalization note. riemannZeta is Mathlib's zeta function; |s.im| is the absolute value of the imaginary part of .
import Mathlib.NumberTheory.LSeries.RiemannZeta import Mathlib.NumberTheory.LSeries.Nonvanishing open Complex
theorem zeta_ne_zero_of_strip_of_two_lt_abs_im (s : ℂ) (h0 : 1 / 2 < s.re) (h1 : s.re < 1)
(him : 2 < |s.im|) : riemannZeta s ≠ 0 := by sorry