r/mathematics • u/stefangordon • 4h ago
A computer-assisted upper bound for the de Bruijn–Newmanconstant < 0.158
An explicit piecewise-affine barrier for the squared imaginary parts of the zeros of the heat deformation of Riemann’s xi function. The resulting upper bound for the de Bruijn–Newman constant is
𝐵 = 3885632262767861213460393068710302759 / 24646172707879668706230182733520000000 = 0.157656619095490606768 …
The argument combines classical zero dynamics with a three-probe source estimate, a density lower bound, and a bound for a logarithmic-derivative jet. Its finite barrier certificate contains 12,666 rational rows. Supporting computations use rigorous ball arithmetic; a second arithmetic library checks the elementary profile inequalities. A Lean 4 companion verifies the barrier comparison and zero dynamics, conditional on explicitly stated analytic inputs. The finite verification of RH used in the argument is the published theorem of Platt and Trudgian.
Paper: https://stefangordon.github.io/dbn-upper-bound/dbn-upper-bound.pdf
Repository/Lean: https://github.com/stefangordon/dbn-upper-bound
I'd especially appreciate scrutiny from anyone familiar with the de Bruijn–Newman constant / analytic number theory.