Orders on groups, their spaces, and complexity

06.03.2014 15:00 - 16:30

V. Harizanov (George Washington U, Washington, D.C., US)

We investigate properties of orders on groups, which respect the algebraic structure. There is a natural topology on the (nonempty) set of such orders, and this space is compact even for a structure with a single binary operation (non necessarily a semigroup). We study the spaces as well as computability-theoretic complexity of orders on groups, both abelian and nonabelian. While not all computable orderable groups have computable orders, many familiar groups contain orders in every Turing degree above a specific degree.

Organiser:

KGRC

Location:
SR 101, 2. St., Währinger Str. 25