SEMINAIRE MERCREDI 3 MARS 2004 14 heures Salle Séminaire 5 Centre de Physique Théorique Marseille-Luminy Edgardo Ugalde Titre: Finite type approximations of Gibbs measures on sofic subshifts Abstract: Consider a Hoder continuous potential \phi defined on the full shift A^\nn, where A is a finite alphabet. Let X\subset A^\nn be a specified sofic subshift. There is a natural nested sequence of subshifts of finite type (X_m) converging to this sofic subshift. To this sequence we can associate a sequence of Gibbs measures (\mu_\phi^m). We prove that this sequence weakly converges to a Gibbs measure \mu_\phi at an exponential speed. Moreover, we show that this measure is the unique equilibrium state of \phi and establish its \psi-mixing property, implying weak Bernoullicity. We enphasize that our approach is contructive and relies on the theory of primitive matrices.