报告题目: Nilcycles and strictly ergodic distal topological models for ergodic measurable distal measure-preserving systems
报告人: 连政星 (Institute of Mathematics, Polish Academy of Science)
摘要: The well-known Jewett-Krieger theorem states that any ergodic m.p.s has a strictly ergodic topological model. Lindenstrauss showed that any ergodic measurable distal measure-preserving system has a minimal distal topological model.Obtaining in addition unique ergodicty turns out to be elusive due to subtle counterexamples. Nevertheless, we introduce certain functions which we name nilcycles whose existence guarantees a strictly ergodic distal topological model. A case where nilcycles exist is in the theory of Host-Kra factors. Joint work with Yonatan Gutman.