On sets without tangents in Galois planes of even order. (English) Zbl 1029.51001
It is shown that the cardinality of a nonempty set of points without tangents in the desarguesian projective plane \(\text{PG}(2,q)\), \(q\) even, is at least \(q+1+ \sqrt{q/6}\) provided that the set is not of even type; and some useful combinatoric properties of this finite geometry are given.
Reviewer: Basri Çelik (Nilüfer-Bursa)
MSC:
| 51A30 | Desarguesian and Pappian geometries |
| 51E21 | Blocking sets, ovals, \(k\)-arcs |
| 51E22 | Linear codes and caps in Galois spaces |
| 51A99 | Linear incidence geometry |
| 51E15 | Finite affine and projective planes (geometric aspects) |
