Abstract
An affine Hjelmslev plane is a near affine Hjelmslev plane with a parallelism. It is proved that every strongly n-uniform near affine Hjelmslev plane possesses an even parallelism and, if n > 2, uneven parallelisms as well. Secondly, we prove that a strongly n-uniform affine Hjelmslev plane A has an extension to a strongly n-uniform projective Hjelmslev plane if and only if the parallelism of A is even. The above results are applied to yield the first known examples of affine Hjelmslev planes which possess no extensions to projective Hjelmslev planes.
Similar content being viewed by others
Bibliography
Artmann, B., ‘Über die Einbettung uniformer affiner Hjelmslev-Ebenen in projektive Hjelmslev-Ebenen’, Abh. Math. Sem. Univ. Hamburg 34 (1970), 127–134.
Bacon, Ph. Y., ‘On Hjelmslev Planes with Small Invariants’, M.A. Thesis, University of Florida, 1971.
Bacon, Ph. Y., ‘On the Extension of Projectively Uniform Affine Hjelmslev Planes’, to appear in Abh. Math. Sem. Univ. Hamburg.
Drake, D. A., ‘Projective Extensions of Uniform Affine Hjelmslev Planes’, Math. Z. 105 (1968), 196–207.
Drake, D. A., ‘On n-Uniform Hjelmslev Planes’, J. Comb. Theory 9 (1970), 267–288.
Drake, D. A., ‘The Translation Groups of n-Uniform Translation Hjelmslev Planes’, Pacific J. Math. 38 (1971), 365–375.
Drake, D. A., ‘The Structure of n-Uniform Translation Hjelmslev Planes’, Trans. 175 (1973), 249–282.
Drake, D. A., ‘Near Affine Hjelmslev Planes’, to appear in J. Comb. Theory, Ser. A.
Kleinfeld, E., ‘Finite Hjelmslev Planes’, Illinois J. Math. 3 (1959), 403–407.
Klingenberg, W., ‘Projektive und affine Ebenen mit Nachbarelementen’, Math. Z. 60 (1954), 384–406.
Klingenberg, W., ‘Desarguessche Ebenen mit Nachbarelementen’, Abh. Math. Sem. Univ. Hamburg 20 (1955), 97–111.
Lüneburg, H., ‘Affine Hjelmslev-Ebenen mit transitiver Translationsgruppe’, Math. Z. 79 (1962), 260–288.
Author information
Authors and Affiliations
Additional information
This research was partially supported by National Science Foundation Research Grant GP-39059. matrix
Rights and permissions
About this article
Cite this article
Drake, D.A. Existence of parallelisms and projective extensions for strongly n-uniform near affine Hjelmslev planes. Geom Dedicata 3, 191–214 (1974). https://doi.org/10.1007/BF00183210
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00183210