A minimum blocking semioval in PG(2, 9)

Autor: Jeremy M. Dover, Keith E. Mellinger, K. L. Wantz
Rok vydání: 2015
Předmět:
Zdroj: Journal of Geometry. 107:119-123
ISSN: 1420-8997
0047-2468
Popis: A blocking semioval is a set of points in a projective plane that is both a blocking set (i.e., every line meets the set, but the set contains no line) and a semioval (i.e., there is a unique tangent line at each point). The minimum size of a blocking semioval is currently known in all projective planes of order < 11, with the exception of PG(2, 9). In this note we show by demonstration of an example that the smallest blocking semioval in PG(2, 9) has size 21 and investigate some properties of this set.
Databáze: OpenAIRE