Distribution of eigenvalues for a large circular domain wall

Determine the distribution of the eigenvalues of the two-dimensional Dirac operator with circular domain wall mass profile \(\kappa=1-2\mathbf{1}_{B_R(0)}\) in the spectral interval \((-1,1)\) as the radius \(R\) tends to infinity.

Background

The paper considers a Dirac operator whose mass changes sign across the boundary of a large disk, so that one topological phase occupies a bounded region and the other occupies its exterior. For every fixed radius, the operator is a compact perturbation of the gapped constant-mass Dirac operator, and its spectrum in (1,1)(-1,1) therefore consists only of eigenvalues.

The authors state that they expect the spectrum in (1,1)(-1,1) to become dense as RR\to\infty, but they do not establish how those eigenvalues are distributed. Understanding this distribution would describe how the finite circular interface approximates the continuous edge spectrum of an unbounded domain wall.

References

Therefore, two questions have emerged: \item What is the distribution of eigenvalues of D in (-1,1)? \item How do eigenvalues of D in (-1,1) contribute to dynamics? We will respond to these questions in a future work.

Reflectionless edge states in Dirac models of topological insulators  (2609.16949 - Drouot, 15 Sep 2026) in Section 1, subsection “Further investigations”