title: Traveling patterns in cellular automata.
abstract: A method to identify the invariant subsets of bi-infinite configurations of cellular automata that propagate rigidly with a constant velocity nu is described. Causal traveling configurations, propagating at speeds not greater than the automaton range, mid R:numid R:</=r, are considered. The sets of traveling configurations are presented by finite automata and its topological entropy is calculated. When the invariant subset of traveling configurations has nonzero topological entropy, the dynamics is dominated by the interaction of domains, composed of traveling patterns of finite size. The sets of traveling patterns and domains are presented by finite automata. End-resolving CA are shown to always have sets of traveling configurations that are spatially periodic with zero entropy, except possibly for traveling configurations at top speed. The elementary CA are examined exhaustively along these lines. (c) 1996 American Institute of Physics.
authors.affiliation: Instituto de Investigacion en Comunicacion Optica, Universidad Autonoma de San Luis Potosi, 78000, San Luis Potosi, SLP, MexicoDepartment of Mathematics and Statistics, Carleton University, Ottawa, Ontario, CanadaCPT, Luminy, Case 907, F-13288 Marseille, Cedex 9, FranceEscuela de Fisica, Universidad Autonoma de Zacatecas, 98000 Zacatecas, Zac., Mexico.
authors.forename: Jesus
authors.initials: J
authors.lastname: Urias
authors.forename: G.
authors.initials: G
authors.lastname: Salazar-Anaya
authors.forename: Edgardo
authors.initials: E
authors.lastname: Ugalde
authors.forename: Agustin
authors.initials: A
authors.lastname: Enciso