L-values and multiplicative Galois module structure

The notion that structural properties of algebraic number fields are encoded in special values of their zeta functions has long had a motivating influence. Two examples of how this can work are the Main Conjecture of Iwasawa theory and the theory of tame additive Galois module structure. Galois module structure of units (more correctly S-units) in number fields can also be viewed from this perspective. There are again `coarse' invariants, which are here cohomological and described by class field theory. And there are, also again, `fine' invariants in the (locally free) class group of the Galois group, which are now (partly conjecturally) determined by values of Artin L-functions at zero.

Refreshments will be served in Math Annex Room 1115, 3:15 p.m.