Logic Seminar
Alexei Kolesnikov
Towson University
Eliminating groupoid imaginaries in first-order theories
Abstract: A recent work of Hrushovski links failure of certain amalgamation properties to definability of groupoids in stable theories. In a joint work with John Goodrick, we provide an explicit construction of such groupoids, show that the groupoids can be non-trivial even in a totally categorical theory, and obtain a way to ``eliminate'', in a certain sense, such groupoids by adding additional sorts to models of the theory. I will describe the results and outline our current research problems.
seminar begins with tea.
Tuesday April 14, 2009 at 4:00 PM in SEO 612