We define the notion of regular point \(p\) in a generalized hexagon and show how a derived geometry at such a point can be defined. We motivate this by proving that, for finite generalized hexagons of order \((s, t)\), this derivation is a generalized quadrangle iff \(s=t\). Moreover, if the genera
Geometrical Constructions of Flock Generalized Quadrangles
โ Scribed by J.A Thas
- Publisher
- Elsevier Science
- Year
- 2001
- Tongue
- English
- Weight
- 121 KB
- Volume
- 94
- Category
- Article
- ISSN
- 0097-3165
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โฆ Synopsis
With any flock F of the quadratic cone K of PG(3, q) there corresponds a generalized quadrangle S(F) of order (q 2 , q). For q odd Knarr gave a pure geometrical construction of S(F) starting from F. Recently, Thas found a geometrical construction of S(F) which works for any q. Here we show how, for q odd, one can derive Knarr's construction from Thas' one. To that end we describe an interesting representation of the point-plane flags of PG(3, q), which can be generalized to any dimension and which can be useful for other purposes. Applying this representation onto Thas' model of S(F ), another interesting model of S(F ) on a hyperbolic cone in PG(6, q) is obtained. In a final section we show how subquadrangles and ovoids of S(F) can be obtained via the description in PG(6, q).
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