Finite representations of pro-p groups and discrete groups.
Finitely Generated pro-2 Groups with a free subgroup of Index 2.
Finiteness Theorems for Deformations of Complexes
We consider deformations of bounded complexes of modules for a profinite group over a field of positive characteristic. We prove a finiteness theorem which provides some sufficient conditions for the versal deformation of such a complex to be represented by a complex of -modules that is strictly perfect over the associated versal deformation ring.
Formally Real Fields with a Simple Description of the Absolute Galois Group.
Frattini Covers and Projective Groups Without the Extension Property.
Free and non-free subgroups of the fundamental group of the Hawaiian Earrings
The space which is composed by embedding countably many circles in such a way into the plane that their radii are given by a null-sequence and that they all have a common tangent point is called “The Hawaiian Earrings”. The fundamental group of this space is known to be a subgroup of the inverse limit of the finitely generated free groups, and it is known to be not free. Within the recent move of trying to get hands on the algebraic invariants of non-tame (e.g. non-triangulable) spaces this space...
Free Pro-...-Groups.
Free pro-p groups with operators.
Frobenius Subgroups of Free Products of Prosolvable Groups.
Groupes analytiques -adiques
Groups with finite automorphism classes of subgroups
Is Whaples' theorem a group theoretical result?
Kneser and Hereditarily Kneser Subgroups of a Profinite Group
2000 Mathematics Subject Classification: 20E18, 12G05, 12F10, 12F99.Given a profinite group Γ acting continuously on a discrete quasi-cyclic group A, certain classes of closed subgroups of Γ (radical, hereditarily radical, Kneser, almost Kneser, and hereditarily Kneser) having natural field theoretic interpretations are defined and investigated. One proves that the hereditarily Kneser subgroups of Γ form a closed subspace of the irreducible spectral space of all closed subgroups of Γ, and a hereditarily...
Mild 2-relator pro--groups.
m-normal theories
Originally, m-independence, ℳ -rank, m-stability and m-normality were defined only for small stable theories. Here we extend the definitions to an arbitrary small countable complete theory. Then we investigate these notions in the new, broader context. As a consequence we show that any superstable theory with countable models is m-normal. In particular, any *-algebraic group interpretable in such a theory is abelian-by-finite.
Neubegründung der Klassenkörpertheorie.
Nilpotent Groups of Hirsch Length Six.
Obstructions for deformations of complexes
We develop two approaches to obstruction theory for deformations of derived isomorphism classes of complexes of modules for a profinite group over a complete local Noetherian ring of positive residue characteristic.
On a New Characterization of Demuskin Groups.
On Amalgamated Products of Profinite Groups.