It was shown by Chinburg and Reid that there exist closed hyperbolic 3-manifolds in which all closed geodesics are simple. Subsequently, Basmajian and Wolpert showed that almost all quasi-Fuchsian 3-manifolds have all closed geodesics simple and disjoint. The natural conjecture arose that the Chinburg-Reid examples also had disjoint geodesics. Here we show that this conjecture is both almost tr...

We study languages of geodesics in lamplighter groups and Thompson’s group F . We show that the lamplighter groups Ln have infinitely many cone types, have no regular geodesic languages, and have 1-counter, context-free and counter geodesic languages with respect to certain generating sets. We show that the full language of geodesics with respect to one generating set for the lamplighter group ...

Hybrid systems are dynamical systems which exhibit both continuous flow and discrete jumps. They are natural modeling formalism for the systems composed of a discrete controller interacting with a physical environment. Since hybrid systems often appear in safetycritical situations, it is non-trivial to study their behavior. A typical way to do that is to explore the reachable state space of a h...