### Bernhard Muhlherr

Universite Libre de Bruxelles

### Twin buildings and groups of Kac-Moody type

**Friday 18th July, 12:05-12:55pm,
Carslaw 173. **
Kac-Moody groups over fields are infinite dimensional
versions of Chevalley groups. As in the case of
Chevalley groups one can associate a building
to each such group. In fact there are two buildings
which are linked by an opposition relation. The triple
consisting of the two buildings and the opposition
relation is the twin building of the group in
question.

In my talk I will give a survey of the classification
of twin buildings and two group-theoretical applications
of them; namely, a generalisation of the Curtis-Tits
presentation to Kac-Moody groups and the solution of
the isomorphism-problem over algebraically closed
fields.