5 problems

Let $H$ be the non-self-adjoint operator considered in the paper, and suppose that $H$ has a spectral singularity. Let the regularized wave operators be the wave operators obtained…

Consider the potential defined in equation, with parameter $\gamma$. Let $k_0$ denote the wave number of its non-self-dual spectral singularity, and let $\gamma_\star^{(j)}$ and…

Let a complex PT-symmetric scattering potential (CPTSSP) be in a parametric regime of broken PT symmetry. Let $E_*$ denote the energy of a spectral singularity (SS), and let…

Let a complex PT-symmetric scattering potential (CPTSSP) be parametrically fixed, and let a spectral singularity (SS) be a real positive energy at which the scattering amplitudes b…

Let $V(x)$ be a complex PT-symmetric scattering potential (CPTSSP) with fixed parameters $(V_1,V_2)$. A spectral singularity, when it exists, occurs at a real positive energy $E_*$…