Pseudo-invariants theory and real phases for systems with non-Hermitian time-dependent Hamiltonians

In this paper, the Lewis-Riesenfeld invariant theory is generalized for the study of systems with non-Hermitian time-dependent Hamiltonians. Explicitly time-dependent pseudo-Hermitian invariants theory, with a time-dependent metric, is developed. We derive a simple relation between the eigenstates of this pseudo-Hermitian invariant and the solutions of the Schrödinger equation. A physical system is treated in detail: the time-dependent Swanson model, where an explicitly time-dependent pseudo-Hermitian invariant is derived as well as their eigenvalues and eigenstates.