Indecomposable endo-permutation modules over p-groups

Gluing endo-permutation modules

In this paper, I show that if p is an odd prime, and if P is a finite p-group, then there exists an exact sequence of abelian groups 0→ T (P )→ D(P )→ lim ←− 1<Q≤P D (

Gluing torsion endo-permutation modules

Let k be a field of characteristic p, and P be a finite p-group, where p is an odd prime. In this paper, we consider the problem of gluing compatible families of endo-permutation modules : being given a torsion element MQ in the Dade group D(NP (Q)/Q), for each non-trivial subgroup Q of P , subject to obvious compatibility conditions, we show that it is always possible to find an element M in t...

Permutation Presentations of Modules over Finite Groups

We introduce a notion of permutation presentations of modules over finite groups, and completely determine finite groups over which every module has a permutation presentation. To get this result, we prove that every coflasque module over a cyclic p-group is permutation projective.

On the Vertices of Indecomposable Modules over Dihedral 2-groups

Let k be an algebraically closed field of characteristic 2. We calculate the vertices of all indecomposable kD8-modules for the dihedral group D8 of order 8. We also give a conjectural formula of the induced module of a string module from kT0 to kG where G is a dihedral group G of order ≥ 8 and where T0 is a dihedral subgroup of index 2 of G. Some cases where we verified this formula are given.

A Construction of Endo-permutation Modules