Mathematical Sciences Seminar - Degrees of undecidability in group theory
When:
—
Venue:
Birkbeck Main Building, Malet Street
No booking required
Many group properties have been shown to be algorithmically impossible to recognise amongst finitely presented groups. For example, one cannot determine if a finite presentation defines a free group or not. However, different properties exhibit different "degrees" of impossibility. In this talk we will discuss Kleene's hierarchy of algorithmically undecidable problems, and show where a few group properties sit in this hierarchy. We will finish by giving a complete characterisation of which sets of integers appear as the set of orders of torsion elements in some finitely presented group.
Contact name:
Department of Economics, Mathematics and Statistics