Skyrme fields, multi-instantons and the $SU(\infty)$-Toda equation

Abstract

We construct Skyrme fields from holonomy of the spin connection of multi-Taub-NUT instantons with the centres positioned along a line in $\mathbb{R}^3.$ Our family of Skyrme fields includes the Taub-NUT Skyrme field previously constructed by Dunajski. However, we demonstrate that different gauges of the spin connection can result in Skyrme fields with different topological degrees. As a by-product, we present a method to compute the degrees of the Taub-NUT and Atiyah-Hitchin Skyrme fields analytically; these degrees are well defined as a preferred gauge is fixed by the $SU(2)$ symmetry of the two metrics. Regardless of the gauge, the domain of our Skyrme fields is the space of orbits of the axial symmetry of the multi-Taub-NUT instantons. We obtain an expression for the induced Einstein-Weyl metric on the space and its associated solution to the $SU(\infty)$-Toda equation.