Speaker:  Allen Yuan (Columbia University)

Title:  Strict units of group rings

Abstract:  Just as an ordinary commutative ring has a group of units, one can associate to any commutative ring spectrum R a topological abelian group of "strict units". These strict units are a basic invariant of R, for instance controlling the types of roots one can adjoint to R. Despite this, there have not been many calculations of strict unit groups. I will survey some results in the area and report on work in progress, joint with Shachar Carmeli and Thomas Nikolaus, on calculating strict units of group rings.