Abstract:
Сountable topological Markov chains (TMC) are considered. It is assumed that
any power of the transition matrix of TMC has finite trace and thus,
for TMC, the dynamical Artin-Mazur zeta function is well-defined.
Furthermore, it is assumed that the following two conditions are satisfied:
1) the radius of convergence of zeta functions for subsystems of TMC
corresponding to submatrices with sufficiently large indexes is greater than
$r(A),$ the radius of convergence of zeta function of original TMC, and
2) zeta function is meromorphic in a disk of radius greater than $r(A).$
These conditions are natural because they take place for countable TMC which
are the symbolic models of one-dimensional piecewise-monotone maps with
positive topological entropy. We show that under these conditions, the
transition matrix of irreducible TMC is $r(A)$-positive and, as a consequence,
zeta function of TMC has simple poles on the circle $|z|=r(A)$ of the complex
plane, and so, TMC has principal ergodic properties of finite TMC (in
particular, there exists a unique measure of maximal entropy)