-auflösbare Gruppen
-essential subgroups of abelian groups. I
-essential subgroups of abelian groups. II.
-essential subgroups of abelian groups. III.
-groups and wreath products
We give criteria for a wreath product to have complemented subgroup-lattice.
-nacci sequences in finite triangle groups.
-theory and stable algebra
-theory of virtually poly-surface groups.
conjecture for Artin groups
The purpose of this paper is to put together a large amount of results on the conjecture for Artin groups, and to make them accessible to non-experts. Firstly, this is a survey, containing basic definitions, the main results, examples and an historical overview of the subject. But, it is also a reference text on the topic that contains proofs of a large part of the results on this question. Some proofs as well as few results are new. Furthermore, the text, being addressed to non-experts, is as...
K2 of p-Adic Group Rings of Abelian p-Groups.
K3 surfaces with a symplectic automorphism of order 11
Kac-Moody groups, hovels and Littelmann paths
We give the definition of a kind of building for a symmetrizable Kac-Moody group over a field endowed with a discrete valuation and with a residue field containing . Due to the lack of some important property of buildings, we call it a hovel. Nevertheless, some good ones remain, for example, the existence of retractions with center a sector-germ. This enables us to generalize many results proved in the semisimple case by S. Gaussent and P. Littelmann. In particular, if , the geodesic segments...
Kappa-Slender Modules
For an arbitrary infinite cardinal , we define classes of -cslender and -tslender modules as well as related classes of -hmodules and initiate a study of these classes.
Kartesisch und residuell abgeschlossene Gruppenklassen [Book]
Kazhdan constants for SL (3, Z).
Kazhdan–Lusztig basis and a geometric filtration of an affine Hecke algebra, II
An affine Hecke algebras can be realized as an equivariant -group of the corresponding Steinberg variety. This gives rise naturally to some two-sided ideals of the affine Hecke algebra by means of the closures of nilpotent orbits of the corresponding Lie algebra. In this paper we will show that the two-sided ideals are in fact the two-sided ideals of the affine Hecke algebra defined through two-sided cells of the corresponding affine Weyl group after the two-sided ideals are tensored by . This...
Kazhdan-Lusztig polynomials: history, problems, and combinatorial invariance.
k-counting automata
In this paper, we define k-counting automata as recognizers for ω-languages, i.e. languages of infinite words. We prove that the class of ω-languages they recognize is a proper extension of the ω-regular languages. In addition we prove that languages recognized by k-counting automata are closed under Boolean operations. It remains an open problem whether or not emptiness is decidable for k-counting automata. However, we conjecture strongly that it is decidable and give formal reasons why we believe...
k-counting automata
In this paper, we define k-counting automata as recognizers for ω-languages, i.e. languages of infinite words. We prove that the class of ω-languages they recognize is a proper extension of the ω-regular languages. In addition we prove that languages recognized by k-counting automata are closed under Boolean operations. It remains an open problem whether or not emptiness is decidable for k-counting automata. However, we conjecture strongly...
k-Homogeneous Groups.