Automata, groups, limit spaces, and tilings

Automata, Groups, Limit Spaces, and Tilings

We explore the connections between automata, groups, limit spaces of self-similar actions, and tilings. In particular, we show how a group acting “nicely” on a tree gives rise to a self-covering of a topological groupoid, and how the group can be reconstructed from the groupoid and its covering. The connection is via finite-state automata. These define decomposition rules, or self-similar tilin...

Cellular Automata and Combinatoric Tilings in Hyperbolic Spaces. A Survey

The first paper on cellular automata in the hyperbolic plane appeared in [37], based on the technical report [35]. Later, several papers appeared in order to explore this new branch of computer science. Although applications are not yet seen, they may appear, especially in physics, in the theory of relativity or for cosmological researches.

Modified Hanoi Towers Groups and Limit Spaces

We introduce the k-peg Hanoi automorphisms and Hanoi self-similar groups, a generalization of the Hanoi Towers groups, and give conditions for them to be contractive. We analyze the limit spaces of a particular family of contracting Hanoi groups, H (k) c , and show that these are the unique maximal contracting Hanoi groups under a suitable symmetry condition. Finally, we provide partial results...

Groups and tilings

Tilings, Tiling Spaces and Topology

To understand an aperiodic tiling (or a quasicrystal modeled on an aperiodic tiling), we construct a space of similar tilings, on which the group of translations acts naturally. This space is then an (abstract) dynamical system. Dynamical properties of the space (such as mixing, or the spectrum of the translation operator) are closely related to bulk properties of individual tilings (such as th...