Non-Hermitian effective dynamics from post-selection protocols

arXiv:2611.03910v1 Announce Type: new Abstract: Multiple seemingly distinct frameworks are commonly proposed to explain the emergence of effective non-Hermitian dynamics in quantum systems coupled to an environment. Furthermore, it remains contested how to properly calculate expectation values or whether thermal equilibrium states exist in non-Hermitian systems. In this work, we show that Feshbach projection, the Lindblad master equation, and the ancilla approach can all be understood through the Kraus map formalism, leading to non-Hermitian time evolution if an appropriate post-selection procedure is enforced.