Logic Seminar

Please note that the time is PST

In joint work with Luca Motto Ros we prove that under analytic determinacy there exists an analytic relation that is not class-wise Borel embeddable into any orbit equivalence relation. The result builds on an unpublished result of Becker from 2001 and aims at better understanding the difference between idealistic and orbit equivalence relations. We will discuss how our result is motivated by other open questions in descriptive set theory and the E1 dichotomy conjecture.