We show that, for every positive real number
and every positive
integer
, there exist
oriented graphs
(with countably many vertices) that are strongly connected, of period
, of Gurevich
entropy
, and
such that
is positive recurrent (thus the topological Markov chain on
admits a measure of
maximal entropy) and
is transient (thus the topological Markov chain on
admits no measure of maximal entropy).