Distributional results for the shortest distance between trajectories of different dynamics

We establish Extreme Value Distributions for the closest encounter between trajectories generated by different maps defined in the same reference phase space.

For a class of strongly mixing maps, we show that the limit distribution depends on the length of the different trajectories and the co-dimension of the associated invariant measures.

It is also modulated by an Extremal Index, that informs on the tendency of nearby points to diverge along with the evolution of their respective dynamics, serving as an indicator of their compatibility.

We give a formula for this quantity for a class of chaotic maps of the interval and for the co-dimension in the case when the respective measures admit densities with isolated zeros and singularities.

We present diverse examples of systems satisfying these assumptions and compute the different parameters modulating the limit distribution.