The Asymptotic Structure of Monopoles in R^3, Calorons, and ALF Instantons
Sergey A. Cherkis, Mark Stern
TL;DR
The paper proves that instantons on ALF spaces, including calorons and monopoles on $\mathbb{R}^3$, always admit a large-radius decomposition into sums of $U(1)$ constituents even without maximal symmetry breaking. It develops a unified framework based on spectral truncations of a Higgs-like operator $\nabla_\theta$, Hilbert bundles, and spectral $\zeta$-functions to control asymptotics, establishing quadratic curvature decay and precise blockwise decompositions labeled by $(\lambda,\beta)$ with $\beta\in\tfrac{1}{2}\mathbb{Z}$ and integrality constraints. The approach extends to $k$-centered Taub-NUT manifolds and calorons, using the same truncation and spectral-geometry toolkit to deduce the asymptotic structure. These results remove a major obstacle to studying the Nahm transform and moduli spaces with arbitrary asymptotic holonomy, enabling a more complete understanding of gauge-theory configurations on ALF geometries. In short, the work provides a robust mechanism to dissect ASD connections into canonical $U(1)$ building blocks at infinity, irrespective of symmetry-breaking assumptions, with broad implications for geometric analysis and mathematical physics.
Abstract
We study the asymptotic structure of instantons on multi-centered Taub-NUT manifolds, calorons, and monopoles on R^3. We show that, without any assumptions on symmetry breaking, these instantons and monopoles asymptotically decompose as a sum of U(1) instantons and monopoles, respectively.
