Penrose Tilings, Chaotic Dynamical Systems and Algebraic K-Theory
  After investigating by examples the unusual and striking elementary properties of the Penrose tilings and the Arnold cat map, we associate a finite symbolic dynamics with finite grammar rules to each of them. Instead of studying these Markovian systems with the help of set-topology, which would give only pathological results, a noncommutative approximately finite C*-algebra is associated to both systems. By calculating the K-groups of these algebras it is demonstrated that this noncommutative point of view gives a much more appropriate description of the phase space structure of these systems than the usual topological approach.   With these specific examples it is conjectured that the methods of noncommutative geometry could be successfully applied to a wider class of dynamical systems. 
Tamas Tasnadi