Von Neumann on measure and ergodic theory
Von Neumann on measure and ergodic theory
According to a currently popular principle of classification, mathematics is the study of various "categories." A category consists of certain "objects" (e.g., groups, topological spaces) and certain "mappings" (e.g., homomorphisms, continuous functions).One possible category has measure spaces for its objects and, correspondingly, measure-preserving transformations for its mappings.The usual distinction between …