“…A modern version of the density operator approach with non-Hermitian Hamiltonians has been proposed relatively recently [4,5,6], where the normalization transformation was introduced. This immediately resulted in an outburst of applications, including entanglement's generation, amplification and protection, decoherence, spin squeezing, dissipative dimers, spin-chain-star systems, kicked rotor models, violations of Leggett-Garg inequality, population dynamics, Bayesian parameter estimation, modifications of the two-point measurement method, macroscopic quantum electrodynamics with a pseudomode, coherence delocalization in coupled-cavity systems, models with non-local initial conditions, nuclear spin ensemble with a reservoir, adiabaticity and entropy dynamics of various two-level dissipative systems, quantum Fisher information and phase estimation without and with decoherence, ground-state cooling of neardegenerate mechanical modes, to mention only a recent literature [7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28].…”