Algebraic Geometry Seminar
Christian Haesemeyer
UIC
Du Bois invariants of singularities and a question of Bass
Abstract: If the Picard group of a Noetherian ring R is equal to that of
R[t], then it stays the same for polynomial rings over R in any number of
variables. Bass asked if the same is true for the Grothendieck group of
vector bundles, or more generally for any algebraic K-group. I will report
on joint work with Cortinas, Walker and Weibel that answers this question;
it turns out that the cohomology of the du Bois complexes appears as a
summand in the K-groups, and classical computations of du Bois invariants of
semiquasihomogeneous surface singularities over the rationals provide
examples for which the answer is \"no\".
Thursday September 6, 2007 at 4:00 PM in SEO 636