�ber rationale Darstellungen von Kettengeometrien als projektive Variet�ten

1986

Der Satz von Tits für PGL2(R), R ein kommutativer Ring vom stabilen Rang 2

1996

Certain permutation groups on sets with distance relation are characterized as groups of projectivities PGL2(R) on the projective line over a commutative ring R of stable rank 2, thus generalizing a classical result of Tits where R is a field.

Ein Axiomensystem f�r partielle affine R�ume

1994

A partial linear space with parallelism is called partial affine space if it is embeddable in an affine space with the same pointset preserving the parallelism. These partial affine spaces will be characterized by a system of three axioms for partial linear spaces with parallelism.

B�schels�tze zur Charakterisierung projektiv darstellbarer Zykelebenen

1979

Lineare Kongruenzen, die aus freien zyklischen Moduln halbeinfacher Algebren bestehen

1978

Dualit�ten mit zwei Geraden aus absoluten Punkten in projektiven Ebenen

1972

Charakterisierung regul�rer Faserungen durch Schlie�ungss�tze

1974

�ber niedrigdimensionale projektive Darstellungen von Kettengeometrien

1985

Characterization of strong chain geometries by their automorphism group

1992

A wide class of chain geometries is characterized by their automorphism group using properties of a distinguished involution.

The generalized André systemsA(F,ß,(gi), (f i), ε)

1988

Charakterisierung von Kettengeometrien �ber semilokalen Algebren

1991

Chain geometries over semilocal rings are characterized as special touching structures possessing a distinguished group of automorphisms fixing two distant points.

Zu einem Satz von H. Lüneburg über verallgemeinerte André-Ebenen

1989

On sets of subspaces closed under reguli

1992

Using a representation of chain geometries where points are certain subspaces of a projective space and chains are reguli, we give an algebraic description of the weak subspaces of the chain geometry (i.e. the subsets of the pointset which are closed with respect to reguli).

Semimodular Locally Projective Lattices of Rank 4 from v.Staudt’s Point of View

1981

We consider groups of projectivities in a certain kind of lattices called “Spaces”,also comprising the circle planes, and give theorems of v.Staudtian type, which characterize those Spaces which can be represented by a sublattice of a projective geometry of rank 4.

On a projective representation of chain geometries

1984

We define a distance d on the set of r-spaces of an n-space. By the transfer of d to the GrasmannianG=G(n, r) we obtain a distinguished class of normal rational curves of order 1, the “1-distance lines’, 1=1,..., r, which are in 1–1-correspondence to the so-called “generalized reguli of type (r, 1)”.

Über den Rang der projektiven Darstellung von Kettengeometrien auf Grassmann-Mannigfaltigkeiten

1985

Erg�nzung zu ?�ber rationale Darstellungen von Kettengeometrien als projektive Variet�ten?

1987

Endliche nichtkommutative Gruppen mit PartitionII und fixpunktfreiemII-Automorphismus

1980

Kollineationen und Schliessungssätze für Ebene Faserungen

1979

Every affine central collineation of a translation plane π induces a special collineation of the projective space π spanned by the spreadF belonging to π. Here the relations between these special collineations of π and certain incidence propositions inF are investigated; so new proofs are given for some characterisations of (A,B)-regular spreads included in [7].

Characterization of chain geometries of finite dimension by their automorphism group

1990

A large class of chain geometries of finite dimension is characterized as strong chain spaces possessing a distinguished group of automorphisms fixing two distant points.

On Finite Translation Structures with Proper Dilatations

1986

Recently, Biliotti and the author obtained a certain number of results on translation structures with proper dilatations including structure-and characterisation-theorems, which here will be reformulated in a different manner, throwing a new light on some of the regarded questions.

Affine Kettengeometrien �ber Jordanalgebren

1996

It is shown that an affine chain geometry over a Jordan algebra can be constructed in a nearly classical manner. Conversely, such chain geometries are characterized as systems of rational normal curves having a group of automorphisms with certain properties.

Translationsstrukturen, die weder axial noch zentral sind

1979

Synthetische Konstruktion affiner M�biusgeometrien

1986

Zur Geometrie der Translationsstrukturen mit eigentlichen Dilatationen

1983

�ber Kreisebenen mit Potenzlinie

1979

Die Schmieghyperebenen an die Veronese-Mannigfaltigkeit bei Beliebiger Charakteristik

1982

By means of linear algebra a base-free definition of a Veronese variety V(n,r) is given and also an illuminating description of its osculating primes from which can be deduced in a general form and without difficulty the phenomena of degeneracy in case of small characteristics. (Instance best known: For characteristic 2 all tangents of a conic are confluent.) The last section investigates special problems for the V(1,r) in characteristic p: So the osculating primes of a V(1,p) intersect its node in a V(1,p-2). Furthermore it becomes clearer why for 2<r<¦K¦−1 no elation can fix a V(1,r) (in case of a perfect field).

Ein Kriterium f�r Quasik�rperA(F, ?, (g i ), (f i ),n)

1991

Eine Beziehung zwischen Regularitätsbedingungen für Faserungen

1979

This is the proof of a theorem which states a relation between some regularity conditions for spreads.

Charakterisierung (A, B)-regul�rer faserungen durch schliessungss�tze

1977

Über die Darstellung affiner Ketten als Normkurven

1985

Projektiv darstellbare stark planare Geometrien vom Rang 4

1976