Minimal and Maximal Semigroups Related to Causal Symmetric Spaces
نویسنده
چکیده
Let G=H be an irreducible globally hyperbolic semisimple symmetric space, and let S G be a subsemigroup containing H not isolated in S. We show that if S o 6 = then there are H-invariant minimal and maximal cones C min C max in the tangent space at the origin such that H exp C min S HZ K (a) exp C max. A double coset decomposition of the group G in terms of Cartan subspaces and the group H is proved. We also discuss the case where G=H is of Cayley type.
منابع مشابه
Characterizing Ordered Bi-Ideals in Ordered Γ-Semigroups
The notion of a &Gamma-semigroup was introduced by Sen [8] in 1981. We can see that any semigroup can be considered as a &Gamma-semigroup. The aim of this article is to study the concept of (0-)minimal and max- imal ordered bi-ideals in ordered &Gamma-semigroups, and give some charac- terizations of (0-)minimal and maximal ordered bi-ideals in ordered &Gamma- semigroups analogous to the charact...
متن کاملFrom minimal geodesics to super symmetric field theories
There are many models for the K-theory spectrum known today, each one having its own history and applications. The purpose of this note is to give an elementary description of eight such models (and certain completions of them) and to relate all of them by canonical maps, some of which are homeomorphisms (rather than just homotopy equivalences). Our survey begins with Raoul Bott’s iterated spac...
متن کاملDuality Relation for the Hilbert Series of Almost Symmetric Numerical Semigroups
We derive the duality relation for the Hilbert series H (d; z) of almost symmetric numerical semigroup S (d) combining it with its dual H ( d; z ) . On this basis we establish the bijection between the multiset of degrees of the syzygy terms and the multiset of the gaps Fj , generators di and their linear combinations. We present the relations for the sums of the Betti numbers of even and odd i...
متن کاملIrreducible Numerical Semigroups
We give a characterization for irreducible numerical semi-groups. From this characterization we obtain that every irre-ducible numerical semigroup is either a symmetric or pseudo-symmetric numerical semigroup. We study the minimal presentations of an irreducible numerical semigroup. Separately, we deal with the cases of maximal embedding dimension and multiplicity 3 and 4.
متن کاملOn classification of maximal nilpotent subsemigroups
We develop a general approach to the study of maximal nilpotent subsemigroups of finite semigroups. This approach can be used to recover many known classifications of maximal nilpotent subsemigroups, in particular, for the symmetric inverse semigroup, the symmetric semigroup, and the factor power of the symmetric group. We also apply this approach to obtain a classification of maximal nilpotent...
متن کامل