Mathematics Seminar: Paradoxicality in groups and rings

Welcome to this seminar with Johan Öinert from Blekinge Tekniska Högskola.

Abstract: The well-known Banach-Tarski paradox is enabled by a certain type of paradoxicality that can arise in groups, leading to paradoxes akin to "1=2", figuratively speaking. Similarly, paradoxicality can occur in rings, manifesting as the failure to have unbounded generating numbers. In this talk, we will explain how the paradoxicality of a group relates to the paradoxicality of a ring graded by that group. The talk is based on joint work with K. Lorensen.