Universal Constraint for Relaxation Rates for Quantum Dynamical Semigroup

A general property of relaxation rates in open quantum systems is discussed. We find an interesting constraint for that universally holds fairly large classes dynamics, e.g., weak coupling regimes, as well entropy nondecreasing evolutions. conjecture this universal, i.e., it valid all dynamical semigroups. The supported by numerical analysis. Moreover, we show the conjectured tight providing a concrete model saturates bound. This universality marks essential step toward physical characterization complete positivity directly verifiable experiments. It provides, therefore, manifestation positivity. Our also has two important implications: provides (i) universal spectra channels and (ii) necessary condition to decide whether given channel consistent with Markovian evolution.