Furutsu-Novikov–like Cross-Correlation–Response Relations for Systems Driven by Shot Noise

We consider a dynamic system that is driven by an intensity-modulated Poisson process with intensity Λ ( t ) = λ ( t ) + ϵ ν ( t ) . We derive an exact relation between the input-output cross-correlation in the spontaneous state ( ϵ = 0 ) and the linear response to the modulation ( ϵ > 0 ). If ϵ is sufficiently small, linear-response theory captures the full response. The relation can be regarded as a variant of the Furutsu-Novikov theorem for the case of shot noise. As we show, the relation is still valid in the presence of additional independent noise. Furthermore, we derive an extension to Cox-process input, which provides an instance of colored shot noise. We discuss applications to particle detection and to neuroscience. Using the new relation, we obtain a fluctuation-response relation for a leaky integrate-and-fire neuron. We also show how the new relation can be used in a remote control problem in a recurrent neural network. The relations are numerically tested for both stationary and nonstationary dynamics. Lastly, extensions to marked Poisson processes and to higher-order statistics are presented.