Tuesday, 3 pm: *Rigidity and algebraic K-theory* (concerning the Borel conjecture), Wolfgang Steimle

## Archive for September, 2009|Monthly archive page

## Seminars 28.9. – 2.10.

In Talk announcement on**September 29, 2009**at

**10:12**

## Let’s talk about your problems!

In Talk announcement on**September 24, 2009**at

**13:42**

Wednesday 30 Sept, 10:00 AM: Presentation and discussion of open problems related to rigidity.

Everybody is invited!

## Seminars 21.-25.9.

In Talk announcement on**September 16, 2009**at

**10:09**

Tuesday 9 am: A Counterexample to Atiyah´s Conjecture I (after Tim Austin), Thomas Schick

Tuesday 3 pm: Borel reducibility, Asger Törnquist

Wednesday 9 am: A Counterexample to Atiyah´s Conjecture II (after Tim Austin), Thomas Schick

Wednesday 3 pm: Cohomology of Lie groups, Tobias Hartnick

Thursday 9 am: Simplicial Volume, Clara Löh

Thursday 3 pm: What is coarse differentiation?, Irene Peng

Friday 9 am: Quantum groups for beginners, David Kyed

## LaTeX in this blog!

In Uncategorized on**September 14, 2009**at

**15:10**

We can use some amount of in this blog. Just put any math command between $ signs, with the word “latex” (followed by a space) right after the first $.

Thus, for instance, if I write this:

$latex \sum_{n=1}^\infty \frac1{n^2} = \frac{\pi^2}6$,

you will see that:

.

Of course, only basic commands will work. Enjoy!

Nicolas

PS: more info here.

## Seminars 14-18.9

In Talk announcement on**September 11, 2009**at

**16:03**

Wed 3pm: Hjorth, Descriptive set theory and equivalence relations.

Abstract: A very general and introductory talk about descriptive set

theory and the parts of the field which connect with countable

equivalence relations.

Thu 9am: Przytycki, Introduction to complexes of groups,.

## Seminar talks (Archiv)

In Talk announcement on**September 9, 2009**at

**15:08**

Just to keep the list of seminar talks up to date and not to lose the information which talks have already be given, I suggest to list past talks in this post. Also, one might use this post to add background material or references to the old talks.

The following talks have already be given:

- Caprace, Kac-Moody groups
- Fabig, Assembly maps
- Hartnick, Bounded cohomology — see also here for references
- Bader, Ergodic actions
- Weinberger, Topological Rigidity
- Sauer, Measure equivalence
- Chatterjee, Algebraic Groups
- Ruping, CAT(0) properties of diagram groups
- Epstein, Orbit equivalence
- Hjorth, Descriptive Set Theory
- Przytycki, Complexes of groups
- Schick, A Counterexample to Atiyah´s Conjecture (after Tim Austin)
- Törnquist, Borel reducibility
- Hartnick, Cohomologies of Lie groups
- Löh, Simplicial Volume
- Peng, Coarse Differentiation
- Kyed, Quantum Groups

## Seminars

In Talk announcement on**September 9, 2009**at

**13:12**

Wed 9am: Bader, Ergodic Theory

Wed 2pm: Weinberger, Topological Rigidity

Thu 9am: Sauer, Measure Equivalence

Thu 2pm: Chatterjee, Algebraic Groups

Fri 9am: Ruping, CAT(0) properties of diagram groups

## Welcome!

In Uncategorized on**September 4, 2009**at

**21:56**

Welcome to the Rigidity blog! This is the place to announce talks, request talks, ask questions, or just comment away.

This site is destined to remain completely informal. Even if you plan to explain your latest idea — or doubt — to just one colleague, please consider announcing it here: a few more guests might just show up.