Bifurcations of thresholds in essential spectra of elliptic operators under localized non-Hermitian perturbations

D. I. Borisov, D. A. Zezyulin, M. Znojil

We consider the operator $$\mathcal{H}={\mathcal{H}}^{\prime }-\frac{{\partial }^2}{\partial x_d^2}\text{on}\omega \times \mathbb{R}$$ subject to the Dirichlet or Robin condition, where a dom…