Regular combings, nonpositive curvature and the quasiconvexity of abelian subgroups
نویسندگان
چکیده
منابع مشابه
Nonpositive curvature of blow - ups
Consider the following situation: MC is a complex manifold of complex dimension n, and DC is a union of smooth complex codimension-one submanifolds (i.e., DC is a smooth divisor). Examples of this situation include: (1) arrangements of projective hyperplanes in CP, as well as various blow-ups of such arrangements along intersections of hyperplanes, (2) nonsingular toric varieties (whereDC is th...
متن کاملNonpositive Curvature and Reflection Groups
Introduction. A space is aspherical if its universal cover is contractible. Examples of aspherical spaces occur in differential geometry (as complete Riemannian manifolds of nonpositive sectional curvature), in Lie groups (as Γ\G/K where G is a Lie group, K is a maximal compact subgroup and Γ is a discrete torsion-free subgroup), in 3-manifold theory and as certain 2-dimensional cell complexes....
متن کاملThe Volume Flux Group and Nonpositive Curvature
We show that a closed nonpositively curved manifold with non-trivial volume flux group has zero minimal volume. It can be seen from the proof that these manifolds admit a finite covering with circle actions whose orbits are homologically essential. LetM be a closed smooth manifold and μ a volume form onM . Denote by Diff the group of μ–preserving diffeomorphisms of M , and by Diff 0 its identit...
متن کاملSimplicial Nonpositive Curvature
We introduce a family of conditions on a simplicial complex that we call local klargeness (k ≥ 6 is an integer). They are simply stated, combinatorial and easily checkable. One of our themes is that local 6-largeness is a good analogue of the nonpositive curvature: locally 6-large spaces have many properties similar to nonpositively curved ones. However, local 6-largeness neither implies nor is...
متن کاملThe number of Fuzzy subgroups of some non-abelian groups
In this paper, we compute the number of fuzzy subgroups of some classes of non-abeilan groups. Explicit formulas are givenfor dihedral groups $D_{2n}$, quasi-dihedral groups $QD_{2^n}$, generalized quaternion groups $Q_{4n}$ and modular $p$-groups $M_{p^n}$.
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Journal of Pure and Applied Algebra
سال: 1993
ISSN: 0022-4049
DOI: 10.1016/0022-4049(93)90009-i