Value-Distribution of the Riemann Zeta-Function along its Julia Lines

Abstract

For an arbitrary complex number $a\neq 0$ we consider the distribution of values of the Riemann zeta-function $ζ$ at the $a$-points of the function $Δ$ which appears in the functional equation $ζ(s)=Δ(s)ζ(1-s)$. These $a$-points $δ_a$ are clustered around the critical line $1/2+i\mathbb{R}$ which happens to be a Julia line for the essential singularity of $ζ$ at infinity. We observe a remarkable average behaviour for the sequence of values $ζ(δ_a)$.