Introduction. The purpose of this work is to introduce the notion of en-tropy as an invariant for continuous mappings.
Rotation Theory has its roots in the theory of rotation numbers for circle homeomorphisms, developed by Poincaré. It is particularly useful for the study and classification of periodic orbits of dynamical systems. It deals with ergodic averages and their limits, not only for almost all points, like in Ergodic Theory, but for all points. We present the… (More)
We prove that if an interval map of positive entropy is perturbed to a compact multidimensional map then the topological entropy cannot drop down a lot if the perturbation is small.
We consider a problem in Mathematical Biology that leads to a question in Graph Theory, which can be solved using an old but not widely known upper estimate of the spectral radius of a nonnegative matrix. We provide a new proof of this estimate.
Combinatorial Dynamics has its roots in Sharkovsky's Theorem. This beautiful theorem describes the possible sets of periods of all cycles of a continuous map of an interval (or the real line) into itself. Here by a cycle I mean a periodic orbit, and by a period its minimal period. Consider the following Sharkovsky's ordering < s of the set N of natural… (More)