An entropy for $ℤ^2$ -actions with finite entropy generators
Tom 157 / 1998
Fundamenta Mathematicae 157 (1998), 209-220 DOI: 10.4064/fm-157-2-3-209-220
We study a definition of entropy for $ℤ^+ × ℤ^+$-actions (or $ℤ^2$-actions) due to S. Friedland. Unlike the more traditional definition, this is better suited for actions whose generators have finite entropy as single transformations. We compute its value in several examples. In particular, we settle a conjecture of Friedland .