Caltech Logo

Logic Seminar

Wednesday, January 16, 2019
2:00pm to 3:00pm
Add to Cal
Linde Hall 255
Dense orbits in the space of subequivalence relations
Forte Shinko, Department of Mathematics, Caltech,

Given a measure-preserving equivalence relation E, there is a Polish space S(E) of subequivalence relations, which admits a natural action of the full group [E]. Does S(E) have a dense orbit? We will present results due to François Le Maître which show that the answer is yes when E is the hyperfinite ergodic equivalence relation, and that the answer is no when E is induced by  a measure-preserving action of a property (T) group.

For more information, please contact Mathematics Department by phone at 626-395-4335 or by email at [email protected].