Alexander Levin : Compatibility of Difference Field Extensions

Posted by , part of the Logic Seminar.

At

March 3, 2009, 4 p.m.

In

SEO 612

Abstract

In this talk we consider the problem of compatibility of difference field extensions, that is, the problem of K-embedding of two difference field extensions L/K and M/K into some difference overfield of K. We are going to start with a brief discussion of the compatibility of classical and differential field extensions. Then we will consider the situation in difference algebra where even two extensions of an ordinary difference field of zero characteristic can be incompatible. After introducing the concepts of limit degree and core of a difference field extension and describing their properties, we will prove a criterion of compatibility for extensions of ordinary difference fields.

seminar begins with tea.