Ergodic theory (Ancient Greek: ergon work, hodos way) is a branch of mathematics that studies dynamical systems with an Invariant measure (intuitively, the stationary distribution) and related problems
An
Ergodic Theory - Stefano Luzzatto - Lecture 01. Introduction to Measure theory, and Probability theory
https://en.wikipedia.org/wiki/Ergodic_theory
Recent Trends in Ergodic Theory and Dynamical Systems
Karma Dajani - An introduction to Ergodic Theory of Numbers (Part 1)