Title
Uniform hyperplanes of finite dual polar spaces of rank 3
Abstract
Let Δ be a finite thick dual polar space of rank 3. We say that a hyperplane H of Δ is locally singular (respectively, quadrangular or ovoidal) if H ∩ Q is the perp of a point (resp. a subquadrangle or an ovoid) of Q for every quad Q of Δ . If H is locally singular, quadrangular, or ovoidal, then we say that H is uniform. It is known that if H is locally singular, then either H is the set of points at non-maximal distance from a given point of Δ or Δ is the dual of Q (6,  q ) and H arises from the generalized hexagon H ( q ). In this paper we prove that only two examples exist for the locally quadrangular case, arising in Q (6, 2) and H (5, 4), respectively. We fail to rule out the locally ovoidal case, but we obtain some partial results on it, which imply that, in this case, the geometry Δ \ H induced by Δ on the complement of H cannot be flag-transitive. As a bi-product, the hyperplanes H with Δ \ H flag-transitive are classified.
Year
DOI
Venue
2001
10.1006/jcta.2000.3136
J. Comb. Theory, Ser. A
Keywords
Field
DocType
uniform hyperplanes,finite dual polar space
Combinatorics,Ovoid,Polar,Polar space,Hyperplane,Mathematics
Journal
Volume
Issue
ISSN
94
2
Journal of Combinatorial Theory, Series A
Citations 
PageRank 
References 
19
4.45
1
Authors
2
Name
Order
Citations
PageRank
A. Pasini1194.45
S. Shpectorov28215.28