Classification of compact homogeneous spaces with invariant symplectic structures.
We introduce a new class of connected solvable Lie groups called -group. Namely a -group is a unimodular connected solvable Lie group with center such that for some in the Lie algebra of , the symplectic for on given by is nondegenerate. Moreover, apart form some technical requirements, it will be proved that a connected unimodular Lie group with center , such that the center of is finite, has discrete series if and only if may be written as , , where is a -group with...
In this paper we seek to describe the structure of self-dual torsion-free LCA groups. We first present a proof of the structure theorem of self-dual torsion-free metric LCA groups. Then we generalize the structure theorem to a larger class of self-dual torsion-free LCA groups. We also give a characterization of torsion-free divisible LCA groups. Consequently, a complete classification of self-dual divisible LCA groups is obtained; and any self-dual torsion-free LCA group can be regarded as an open...
[For the entire collection see Zbl 0742.00067.]For the purpose of providing a comprehensive model for the physical world, the authors set up the notion of a Clifford manifold which, as mentioned below, admits the usual tensor structure and at the same time a spin structure. One considers the spin space generated by a Clifford algebra, namely, the vector space spanned by an orthonormal basis satisfying the condition , where denotes the unit scalar of the algebra and () the nonsingular Minkowski...
In this paper we prove that the system of all closed convex -subgroups of a convergence -group is a Brouwer lattice and that a similar result is valid for radical classes of convergence -groups.
We show that zero-dimensional nondiscrete closed subgroups do exist in Banach spaces E. This happens exactly when E contains an isomorphic copy of . Other results on subgroups of linear spaces are obtained.
The main results of the paper are: Proposition 0.1. A group G acting coarsely on a coarse space (X,𝓒) induces a coarse equivalence g ↦ g·x₀ from G to X for any x₀ ∈ X. Theorem 0.2. Two coarse structures 𝓒₁ and 𝓒₂ on the same set X are equivalent if the following conditions are satisfied: (1) Bounded sets in 𝓒₁ are identical with bounded sets in 𝓒₂. (2) There is a coarse action ϕ₁ of a group G₁ on (X,𝓒₁) and a coarse action ϕ₂ of a...