J. Andre constructed a skewaffine structure as a group space of a normally transitive group. In this paper his construction is used to describe the structure of the set of circles not passing through a point of a Laguerre plane. Sufficient conditions to ensure that this structure is a skewaffine plane are given.
Dieser Artikel befasst sich mit einigen Fragen der kinematischen Geometrie auf der Laguerreschen Gruppe -Gruppe). Die -Gruppe wird durch die Gruppe der direkten linearen gebrochenen Transformationen der erweiterten dualen Ebene (ein Modell der -Ebene) repräsentiert. Im Artikel werden die Begriffe der -Bewegung, der Geschwindigkeiten der -Bewegung im gegeben Punkt und in der gegebenen Phase , der Vektorfelder der Geschwindigkeiten, der Momentanpole definiert und untersucht. Die Phasen der...
In this paper the plane Laguerre’s geometry in the augmented plane of dual numbers is presented. Basic integral and differential invariants of -curves in the plane are deduced, i.e. the -curve arc, -curvature, -minimal curves, -circle. Furthermore the contact of -curves, -osculating circle, -evolute of a curve and some special -motions are studied from the point of view of -Differential geometry.
Some examples of affine planes non-extensible to a Laguerre plane are studied and conditions for the uniqueness of a Laguerre extension are given.
There are three kinds of Benz planes: Möbius planes, Laguerre planes and Minkowski planes. A Minkowski plane satisfying an additional axiom is connected with some other structure called a nearaffine plane. We construct an analogous structure for a Laguerre plane. Moreover, our description is common for both cases.
The group generated by double tangency symmetries in a Laguerre plane is investigated. The geometric classification of involutions of a symmetric Laguerre plane is given. We introduce the notion of projective automorphisms using the double tangency and parallel perspectivities. We give the description of the groups of projective automorphisms and automorphisms generated by double tangency symmetries as subgroups of the group M(𝔽,ℝ) of automorphisms of a chain geometry Σ(𝔽,ℝ) following Benz.