Radu Munteanu
University of Bucharest, Bucharest, Romania

We introduce a notion of inverse entropy for an arbitrary measure preserving endomorphism on a probability space. We provide a general formula for inverse measure-theoretic entropy relating it to the folding entropy. We compute the inverse entropy for some concrete examples. The inverse entropy can differentiate between endomorphisms which have the same forward measure theoretic entropy. We study the relationship between inverse measure-theoretic entropy and toplogical inverse entropy. This is joint work with Eugen Mihailescu.