scholarly journals Intertwining automorphisms in finite incidence structures

1989 ◽  
Vol 117 ◽  
pp. 25-34 ◽  
Author(s):  
Alan Camina ◽  
Johannes Siemons
2017 ◽  
Vol 104 (1) ◽  
pp. 1-12
Author(s):  
JOHN BAMBERG ◽  
JOANNA B. FAWCETT ◽  
JESSE LANSDOWN

In Bachmann [Aufbau der Geometrie aus dem Spiegelungsbegriff, Die Grundlehren der mathematischen Wissenschaften, Bd. XCVI (Springer, Berlin–Göttingen–Heidelberg, 1959)], it was shown that a finite metric plane is a Desarguesian affine plane of odd order equipped with a perpendicularity relation on lines and that the converse is also true. Sherk [‘Finite incidence structures with orthogonality’, Canad. J. Math.19 (1967), 1078–1083] generalised this result to characterise the finite affine planes of odd order by removing the ‘three reflections axioms’ from a metric plane. We show that one can obtain a larger class of natural finite geometries, the so-called Bruck nets of even degree, by weakening Sherk’s axioms to allow noncollinear points.


1986 ◽  
Vol 2 (1) ◽  
pp. 339-346 ◽  
Author(s):  
J. Csima ◽  
Z. Füredi

1980 ◽  
Vol 14 (2) ◽  
pp. 174-181
Author(s):  
Marilena Barnabei ◽  
Giorgio Nicoletti

1967 ◽  
Vol 19 ◽  
pp. 1078-1083 ◽  
Author(s):  
F. A. Sherk

An incidence structure consists of two sets of elements, called points and blocks, together with a relation, called incidence, between elements of the two sets. Well-known examples are inversive planes, in which the blocks are circles, and projective and affine planes, in which the blocks are lines. Thus in various examples of incidence structures, the blocks may have various interpretations. Very shortly, however, we shall impose a condition (Axiom A) which ensures that the blocks behave like lines. In anticipation of this, we shall refer to the set of blocks as the set of lines. Also, we shall employ the usual terminology of incidence, such as “lies on,” “passes through,” “meet,” “join.” etc.


1980 ◽  
Vol 52 (1-2) ◽  
pp. 141-156 ◽  
Author(s):  
George Markowsky ◽  
Andrew Wohlgemuth
Keyword(s):  

10.29007/d3ls ◽  
2018 ◽  
Author(s):  
Jesse Alama

This note reports on some experiments, using a handful of standard automated reasoning tools, for exploring Steinitz-Rademacher polyhedra, which are models of a certain first-order theory of incidence structures. This theory and its models, even simple ones, presents significant, geometrically fascinating challenges for automated reasoning tools are.


1992 ◽  
Vol 106-107 ◽  
pp. 383-389 ◽  
Author(s):  
Fred Piper ◽  
Peter Wild
Keyword(s):  

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