Low energy resolvent asymptotics of the multipole Aharonov--Bohm Hamiltonian
T. J. Christiansen, K. Datchev, M. Yang
TL;DR
This work derives low-energy resolvent expansions for the Aharonov–Bohm Hamiltonian with multiple poles, revealing that the total flux $\beta=\sum_k \alpha_k$ dictates distinct analytic structures. When $\beta$ is an integer, the operator is conjugate to a compact perturbation of the Laplacian, yielding a three-term resolvent expansion with logarithmic terms; for non-integer $\beta$, a model resolvent $P_{\beta}$ governs the near-zero behavior, and the resolvent exhibits a mixed expansion with powers determined by $|\beta|$ and $1-|\beta|$. The resolvent has meromorphic continuation to the logarithmic cover $\Lambda$ (and to $\Lambda_q$ for rational $\beta$), and these expansions underpin the long-time wave asymptotics, showing an interpolation between even- and odd-dimensional scattering depending on $\beta$. The results extend the low-energy scattering theory to multi-pole Aharonov–Bohm systems and provide explicit leading-order terms and structural insights into the zero-energy regime. This has implications for understanding wave propagation and decay in magnetic systems with multiple topological singularities.
Abstract
We compute low energy asymptotics for the resolvent of the Aharonov--Bohm Hamiltonian with multiple poles for both integer and non-integer total fluxes. For integral total flux we reduce to prior results in black-box scattering while for non-integral total flux we build on the corresponding techniques using an appropriately chosen model resolvent. The resolvent expansion can be used to obtain long-time wave asymptotics for the Aharonov--Bohm Hamiltonian with multiple poles. An interesting phenomenon is that if the total flux is an integer then the scattering resembles even-dimensional Euclidean scattering, while if it is half an odd integer then it resembles odd-dimensional Euclidean scattering. The behavior for other values of total flux thus provides an `interpolation' between these.
