Chaos for endomorphisms of completely metrizable groups and linear operators on Fréchet spaces

Using the techniques in topological dynamics, we give a uniform treatment of Li-Yorke chaos, mean Li-Yorke chaos and distributional chaos for continuous endomorphisms of completely metrizable groups, and characterize three kinds of chaos (resp. extreme chaos) in term of the existence of corresponding semi-irregular points (resp. irregular points). We demonstrate some inner automorphisms of Polish groups to illustrate the results. We also apply the results to the chaos theory of continuous linear operators on Fréchet spaces, which improves some results in the literature.