An ergodic theorem for non-invariant measures

Maria Carvalho, Fernando Moreira

Given a space $X$, a $\sigma$-algebra $\mathfrak{B}$ on $X$ and a measurable map $T:X\to X$, we say that a measure $\mu$ is half-invariant if, for any $B\in \mathfrak{B}$, we have $μ(T^…