## Logic Seminar

Douglas Ulrich

Maryland

Borel Complexity and the Schroder-Bernstein Property

**Abstract:**Borel Complexity and the Schroder-Bernstein Property I describe some new techniques for proving non-Borel reducibility results, and give some applications, including: suppose the collection of countable models of a sentence sigma of L_{omega_1 omega} satisfies the Schroder-Bernstein property, that is, if two countable models are bi-embeddable then they are isomorphic. Then, assuming a mild large cardinal, sigma is not Borel complete.

We meet for lunch at noon on the first floor of SEO.

Tuesday October 10, 2017 at 4:00 PM in SEO 427