Por Alexandre Tavares Baraviera (Universidade Federal do Rio Grande do Sul).

Binary trees are the Cayley graphs of the free monoid with two generators a and b. Considering configurations where each vertex has an element of some finite alphabet it is possible to define very naturally the action of a and b, that is some sense are similar to the well-known shift.   

In the talk I would like to explore some properties of two particular cases:  

First, the entropy for subshifts where the allowed transitions are defined by two matrices A and B, one for each generator (this is joint with Alex Becker and Andressa Cordeiro).

Second, the definition of a possible substitution dynamics on the trees where a non-periodic pattern appears (this is joint with Renaud Leplaideur).