**SMS scnews item created by Stephan Tillmann at Tue 31 May 2016 1608**

Type: Seminar

Modified: Tue 31 May 2016 1609

Distribution: World

Expiry: 30 Aug 2016

**Calendar1: 1 Jun 2016 1200-1300**

**CalLoc1: Carslaw 535A**

CalTitle1: K-theory of singularities

Auth: tillmann@p710.pc (assumed)

### Geometry & Topology

# K-theory of singularities

### Christian Haesemeyer (UCLA/Melbourne)

Wednesday 1 June 2016 from 12:00–13:00 in Carslaw 535A

Please join us for lunch after the talk!

**Abstract:**
Algebraic K-theory is, fundamentally, an approach to studying
linear algebra over general rings. For example, K-theory tells us that any
idempotent matrix whose entries are polynomials with coefficients in the
ring of germs of functions at a smooth point on an algebraic variety is
stably diagonalisable. This is false if we use germs of functions at a
singular point instead. In this talk I will try to explain how methods from
abstract homotopy theory, commutative algebra and algebraic geometry
(developed to study K-theory in a joint project with G. Cortinas, M. Walker,
C. Weibel and in part M. Schlichting) can be used to measure this failure in
terms of the algebra and geometry of the singularity in question.