Ruelle Operator for Continuous Potentials and DLR-Gibbs Measures Leandro Cioletti Artur O. Lopes Departamento de Matem´atica - UnB Departamento de Matem´atica - UFRGS 70910-900, Bras´ılia, Brazil 91509-900, Porto Alegre, Brazil
[email protected] [email protected] Manuel Stadlbauer Departamento de Matem´atica - UFRJ 21941-909, Rio de Janeiro, Brazil
[email protected] October 25, 2019 Abstract In this work we study the Ruelle Operator associated to a continuous potential defined on a countable product of a compact metric space. We prove a generaliza- tion of Bowen’s criterion for the uniqueness of the eigenmeasures. One of the main results of the article is to show that a probability is DLR-Gibbs (associated to a continuous translation invariant specification), if and only if, is an eigenprobability for the transpose of the Ruelle operator. Bounded extensions of the Ruelle operator to the Lebesgue space of integrable functions, with respect to the eigenmeasures, are studied and the problem of exis- tence of maximal positive eigenfunctions for them is considered. One of our main results in this direction is the existence of such positive eigenfunctions for Bowen’s potential in the setting of a compact and metric alphabet. We also present a version of Dobrushin’s Theorem in the setting of Thermodynamic Formalism. Keywords: Thermodynamic Formalism, Ruelle operator, continuous potentials, Eigenfunc- tions, Equilibrium states, DLR-Gibbs Measures, uncountable alphabet. arXiv:1608.03881v6 [math.DS] 24 Oct 2019 MSC2010: 37D35, 28Dxx, 37C30. 1 Introduction The classical Ruelle operator needs no introduction and nowadays is a key concept of Thermodynamic Formalism.