Kinetic Equality for Susceptibility and Dynamical Activity

We show a general kinetic equality for susceptibilities (KSE) of general fluctuating quantities and for the dynamical activity of nonequilibrium systems described by Markovian master equations. As special limiting cases, KSE reproduces the so-called kinetic uncertainty relation and its multivariate extension. To derive KSE, we also show a kinetic generalization of fluctuation theorem, and an equality for the susceptibility and the observable-frenetic covariance. Hence, KSE provides a master relation of these nonequilibrium kinetic relations.