Unramified cohomology of alternating groups
We prove vanishing results for the unramified stable cohomology of alternating groups.
Untergruppenkriterien für abelsche Gruppen.
Using the Frattini subgroup and independent generating sets to study RWPri geometries.
Valuations and group algebras
Valuations in groups and rings
Valuations on free resolutions and higher geometric invariants of groups.
Valued Groups.
Vanishing of the first reduced cohomology with values in an -representation
We prove that the first reduced cohomology with values in a mixing -representation, , vanishes for a class of amenable groups including connected amenable Lie groups. In particular this solves for this class of amenable groups a conjecture of Gromov saying that every finitely generated amenable group has no first reduced -cohomology. As a byproduct, we prove a conjecture by Pansu. Namely, the first reduced -cohomology on homogeneous, closed at infinity, Riemannian manifolds vanishes. We also...
Vanishing theorems and conjectures for the 2-homology of right-angled Coxeter groups.
Variational problems for riemannian functionals and arithmetic groups
Varieties of half lattice-ordered groups of monotonic permutations of chains
Veech Groups of Loch Ness Monsters
We classify Veech groups of tame non-compact flat surfaces. In particular we prove that all countable subgroups of ) avoiding the set of mappings of norm less than 1 appear as Veech groups of tame non-compact flat surfaces which are Loch Ness monsters. Conversely, a Veech group of any tame flat surface is either countable, or one of three specific types.
Virtual and welded links and their invariants.
Volume of spheres in doubling metric measured spaces and in groups of polynomial growth
Let be a compactly generated locally compact group and let be a compact generating set. We prove that if has polynomial growth, then is a Følner sequence and we give a polynomial estimate of the rate of decay of Our proof uses only two ingredients: the doubling property and a weak geodesic property that we call Property (M). As a matter of fact, the result remains true in a wide class of doubling metric measured spaces including manifolds and graphs. As an application, we obtain a -pointwise...
Volumes of discrete groups and topological complexity of homology spheres.
Weak potency of fundamental groups of graphs of groups.
Weighted -cohomology of Coxeter groups based on barycentric subdivisons.
What Does a Basis of F(a, b) Look Like?
When is Zn the only Group of Order n?
Which 3-manifold groups are Kähler groups?
The question in the title, first raised by Goldman and Donaldson, was partially answered by Reznikov. We give a complete answer, as follows: if can be realized as both the fundamental group of a closed 3-manifold and of a compact Kähler manifold, then must be finite—and thus belongs to the well-known list of finite subgroups of , acting freely on .