Topology of Circle Homeomorphisms
摘要
We collect in the following a list of basic definitions in dynamics. A dynamical system is a map \(f:X\to X\) where X is a metric space called the “state space” of the system. Starting with a state \(x\in X\) , f describes how the state changes with the time. Namely after n seconds the state x becomes \(x_n=f^n(x)\) , where the iteration \(f^n\) is defined by \(\displaystyle f^n=f\circ f^{n-1} \text{and} f^0 = id_X. \)