Published online by Cambridge University Press: 20 March 2023
Let $({\mathbb X}, T)$ be a subshift of finite type equipped with the Gibbs measure
$\nu $ and let f be a real-valued Hölder continuous function on
${\mathbb X}$ such that
$\nu (f) = 0$. Consider the Birkhoff sums
$S_n f = \sum _{k=0}^{n-1} f \circ T^{k}$,
$n\geqslant 1$. For any
$t \in {\mathbb R}$, denote by
$\tau _t^f$ the first time when the sum
$t+ S_n f$ leaves the positive half-line for some
$n\geqslant 1$. By analogy with the case of random walks with independent and identically distributed increments, we study the asymptotic as
$ n\to \infty $ of the probabilities
$ \nu (x\in {\mathbb X}: \tau _t^f(x)>n) $ and
$ {\nu (x\in {\mathbb X}: \tau _t^f(x)=n) }$. We also establish integral and local-type limit theorems for the sum
$t+ S_n f(x)$ conditioned on the set
$\{ x \in {\mathbb X}: \tau _t^f(x)>n \}.$