Resumen de A note on quasi-similarity of Koopman operators

K. Fraczek, Mariusz Lemanczyk

• Answering a question of A. Vershik we construct two non-weakly isomorphic ergodic automorphisms for which the associated unitary (Koopman) representations areMarkov quasi-similar.We also discuss metric invariants of Markov quasi-similarity in the class of ergodic automorphisms.