Resumen de A Note on the Ergodic Theorem

Maria Pires de Carvalho, Fernando Jorge Moreira

• Given a space X, a σ-algebra B on X and a measurable map T : X → X, we say that a measure μ is half-invariant by T if, for any B ∈ B, we have μ T −1(B) ≤ μ(B). We will present a generalization of Birkhoff ergodic theorem to σ-finite half-invariant measures.