A minimum blocking semioval in PG(2, 9)
Autor: | Jeremy M. Dover, Keith E. Mellinger, K. L. Wantz |
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Rok vydání: | 2015 |
Předmět: |
Discrete mathematics
Blocking (radio) Tangent 020206 networking & telecommunications 0102 computer and information sciences 02 engineering and technology 01 natural sciences Set (abstract data type) Combinatorics Blocking set 010201 computation theory & mathematics Line (geometry) 0202 electrical engineering electronic engineering information engineering Order (group theory) Point (geometry) Geometry and Topology Projective plane Mathematics |
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 |
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