Euler Characteristics and Duality in Riemann Functions and the Graph Riemann-Roch Rank

Nicolas Folinsbee, Joel Friedman

By a {\em Riemann function} we mean a function $f:{\mathbb{Z}}^n\to \mathbb{Z}$ such that $f(\mathbf{d})=f(d_1,\dots ,d_n)$ is equals $0$ for $\mathrm{deg}(\mathbf{d})=d_1+\cdots +d_n$ s…