*Wissenschaftliches Programm* *Liste der Vortragenden*

**Sektion 12**

Donnerstag, 21.09.2000,
15.00–15.20 Uhr, WIL C 102

#### Hubert Kiechle, Universität Hamburg

An F-pair (N, ) consists of two groups (N, +) and such that acts as an automorphism group on N,
and such that for every \ {1}, the map - 1 : N N is bijective. We call (N, ) finite if N is
finite. In this case the condition is equivalent to the condition that acts fixed point free on
N.

A finite F-pairs gives rise to the 2-designs (N, B) with the set B := {a + b; a, b N, a /= 0}. The
F-pair and the design are called circular if |B B'| __<__ 2 for all B, B' B. We’ll present some new results
on the circularity of F-pairs with non-abelian .