Newton flows for elliptic functions III Classification of $3^{\text{rd}}$ order Newton graphs

Abstract

A Newton graph of order $r(⩾2)$ is a cellularly embedded toroidal graph on $r$ vertices, $2r$ edges and $r$ faces that fulfils certain combinatorial properties (Euler, Hall). The significance of these graphs relies on their role in the study of structurally stable elliptic Newton flows - say $\overline{\stackrel{ˉ}{\mathcal{N}}}(f)$ - of order $r$, i.e. desingularized continuous versions of Newton's iteration method for finding zeros for an elliptic function $f$ (of order $r$). In previous work we established a representation of these flows in terms of Newton graphs. The present paper results into the classification of all $3^{\text{rd}}$ order Newton graphs, implying a list of all nine possible $3^{\text{rd}}$ order flows $\overline{\stackrel{ˉ}{\mathcal{N}}}(f)$ (up to conjugacy and duality).

13 pages, 13 figures