The series Springer Proceedings in Physics, founded in 1984, is devoted to timely reports of
state-of-the-art developments in physics and related sciences. Typically based on material …

Closed formula for the metric in the Hilbert space of a -symmetric model Page 1 Journal of
Physics A: Mathematical and General Closed formula for the metric in the Hilbert space of a -symmetric …

We explore the Hamiltonian operator, where is the Dirac delta function and z is an arbitrary
complex coupling constant. For a purely imaginary z, H has a spectral singularity at. For Re …

One-dimensional scattering mediated by non-Hermitian Hamiltonians is studied. A
schematic set of models is used which simulates two point interactions at a variable strength …

This chapter commences with a discussion on the challenge of non‐Hermiticity in quantum
physics. It talks about new classes of quantum bound states and their probabilistic …

For a quantum Hamiltonian H= H (λ), the observability of the energies E may be robust
(whenever all E are real at all λ) or, otherwise, conditional. Using a pseudo-Hermitian family …

We consider the operator Ly=−(d/dx) 2 y+ x 2 y+ w (x) y, y in L 2 (ℝ), Ly=-
(d/dx)^2y+x^2y+w(x)y,\quadyinL^2(R), where w (x)= sδ (x− b)+ tδ (x+ b), b≠ 0 real, s, t∈ ℂ …

For the needs of non-perturbative quantum theory, an upgraded concept of solvability is
proposed. In a broader methodical context, the innovation involves Schrödinger equations …

The physically admissible solutions of the-symmetric Scarf I potential are identified in the
domain of real and complex energies. It is found that generally there are no admissible …

We investigate the effects of competition between two complex, $\mathcal {PT} $-symmetric
potentials on the $\mathcal {PT} $-symmetric phase of a" particle in a box". These potentials …