We present an strategy for the derivation of a time-dependent Dyson map which ensures simultaneously the unitarity of the time evolution and the observability of the whole time-dependent non-Hermitian Hamiltonian or parts ...

We describe properties of a Hermitian matrix M ∈ Mn(C) having minimal quotient norm in the following sense: M M + D for all real diagonal matrices D ∈ Mn(C). Here denotes the operator norm. We show a constructive method ...

High accuracy energies of low-lying excited states, in molecular systems,have been determined by means of a procedure which combines the G-particle-holehypervirial (GHV) equation method (Alcoba et al. in Int J Quantum Chem ...

© 2021 Elsevier Inc.We introduce a transfer matrix method for the spectral analysis of discrete Hermitian operators with locally finite hopping. Such operators can be associated with a locally finite graph structure and ...

We generalize a recently proposed algebraic method in order to treat non-Hermitian Hamiltonians. The approach is applied to several quadratic Hamiltonians studied earlier by other authors. Instead of solving the Schrödinger ...

The equation obtained by mapping the matrix representation of the Schrödinger equation with the 2nd-order correlation transition matrix elements into the 2-body space is the so called correlation contracted Schrödinger ...