## Abstract In a previous paper 1, all point sets of minimum size in __PG__(2,__q__), blocking all external lines to a given irreducible conic ${\cal C}$, have been determined for every odd __q__. Here we obtain a similar classification for those point sets of minimum size, which meet every externa
Nuclei of sets of q + 1 points in PG(2, q) and blocking sets of Redei type
β Scribed by A.A Bruen
- Publisher
- Elsevier Science
- Year
- 1990
- Tongue
- English
- Weight
- 159 KB
- Volume
- 55
- Category
- Article
- ISSN
- 0097-3165
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π SIMILAR VOLUMES
It is shown that for fixed 1 ~ 0, if X C PG (d, q) contains (1 + ~)q~ points, then the number of r-fiats spanned by X is at least C(r.)q (r+l)ts+l-r), i.e. a positive fraction of the number of r-fiats in PG(s + 1,q).
In this paper we investigate qz/4-sets of type (O,q/4,q/2) in projective planes of order q=O(mod4). These sets arise in the investigation of regular triples with respect to a hyperoval. Combinatorial properties of these sets are given and examples in Desarguesian projective planes are constructed.
The automorphism group of the set of 12 points associated with an apolar system of conics is determined. A complete (q -&arc for q = 13 can be obtained as a special case. The orbits of its automorphism group are also described. 0 I Y Y ~ John Wile?. & Sons, h e .
## Abstract We determine the distribution of 3β(__q__ + 1,__k__,Ξ») designs, with __k__ Ο΅ {4,5}, among the orbits of __k__βelement subsets under the action of PSL(2,__q__), for __q__ Ο΅ 3 (mod 4), on the projective line. As a consequence, we give necessary and sufficient conditions for the existence