## Abstract The size of large minimal blocking sets is bounded by the Bruen–Thas upper bound. The bound is sharp when __q__ is a square. Here the bound is improved if __q__ is a non‐square. On the other hand, we present some constructions of reasonably large minimal blocking sets in planes of non‐p
Largest minimal blocking sets in PG(2,8)
✍ Scribed by J. Barát; S. Innamorati
- Publisher
- John Wiley and Sons
- Year
- 2003
- Tongue
- English
- Weight
- 120 KB
- Volume
- 11
- Category
- Article
- ISSN
- 1063-8539
No coin nor oath required. For personal study only.
✦ Synopsis
Abstract
Bruen and Thas proved that the size of a large minimal blocking set is bounded by $q \cdot {\sqrt{q}} + 1$. Hence, if q = 8, then the maximal possible size is 23. Since 8 is not a square, it was conjectured that a minimal blocking 23‐set does not exist in PG(2,8). We show that this is not the case, and construct such a set. We prove that this is combinatorially unique. We also complete the spectrum problem of minimal blocking sets for PG(2,8) by showing a minimal blocking 22‐set. © 2003 Wiley Periodicals, Inc. J Combin Designs 11: 162–169, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jcd.10035
📜 SIMILAR VOLUMES
## 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
The reactions of water-soluble phosphanes P(CH,OH), (1) and Ph2PCH20H (2) with NaAuC14 in aqueous or alcoholic media, produced the water/alcoholic-soluble Au' complexes [Au(P(CH,OH),),]+ (3) and [Au(Ph2PCH20H):J+ (4) in near quantitative yields. The X-ray structures of 3 and 4, reported in this pape