The Gregory function and its completed Gregory transform

Abstract

We study the entire interpolation \[ \mathcal{G}(z)=\int_0^1 \binom{x}{z}\,dx \] of the Gregory coefficients. Its completion satisfies the positive Markov-transform identity \[ \frac{πz}{\sin(πz)}\mathcal{G}(z) =\sum_{n=1}^{\infty}\frac{n\left|G_n\right|}{n-z}. \] Consequently, every zero is real and simple; the negative zeros are the integers $-1,-2,\dots$, and one zero ${\rho }_n$ lies in each $(n,n+1)$. We derive complete logarithmic asymptotics for ${\rho }_n-n$, determine the Cartwright growth and canonical products of $\mathcal{G}$, and realize $1/{\rho }_n$ spectrally. The resulting relative determinant yields \[ γ=\sum_{n=1}^{\infty}\left(\frac{1}{n}-\frac{1}{ρ_n}\right). \]

29 pages