Dynamical Resistance Day

Title: Escape of entropy (video)

In many classical compact settings, entropy is upper semicontinuous, i.e., given a convergent sequence of invariant probability measures, the entropy of the limit measure is at least the limsup of the entropies of the sequence. There are only a few results of this type for non-compact cases since both mass and entropy can escape. In this talk I’ll describe how this can happen in the context of countable Markov shifts and give continuity results recently proved with Godofredo Iommi and Anibal Velozo.