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On (q + t)-arcs of type (0, 2, t) in a desarguesian plane of order q

Published online by Cambridge University Press:  24 October 2008

Gábor Korchmáros
Affiliation:
Department of Mathematics, University of Basilicata, 85100 Potenza, Italy
Francesco Mazzocca
Affiliation:
Department of Mathematics and its Applications, University of Napoli, via Mezzocannone 8, 80134 Napoli, Italy

Extract

This paper is concerned with certain point-sets T in a projective plane PG (2, q) over GF (q) which have only three characters with respect to the lines. We assume throughout this paper that for any line l of π

where

It is easily seen that if t = 1 then T is a (q + 1)-arc, i.e. an oval; otherwise T is a (q+t, t)-arc of type (0, 2, t). Therefore (q+t, t)-arcs of type (0, 2, t) appear to be a generalization of ovals and there are interesting connections between ovals and (q + t, t)-arcs of type (0, 2, t) from various points of view. Our purpose is to investigate such particular (k, t)-arcs using some ideas of B. Segre developed for ovals in three fundamental papers [16, 17, 18]. For these papers and more recent results in this direction the reader is referred to [6], chapter 10 and [9]. General results concerning (k, n)-arcs may be found in [6], chapter 12; see also [4, 7, 20, 23].

Type
Research Article
Copyright
Copyright © Cambridge Philosophical Society 1990

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References

REFERENCES

[1]Cherowitzo, W.. Hyperovals in Desarguesian planes of even order. Ann. Discrete Math. 37 (1988), 8794.CrossRefGoogle Scholar
[2]de Vito, P. and Melone, N.. Una caratterizzazione delle ovali nei disegni simmetrici. Ricerche Mat. (To appear.)Google Scholar
[3]Glynn, D.. Two new sequences of ovals in finite Desarguesian planes of even order. In Combinatorial Mathematics X, Lecture Notes in Math., vol. 1036 (Springer-Verlag, 1983), pp. 217219.CrossRefGoogle Scholar
[4]Hill, R.. Some problems concerning (k, n.)-arcs in finite projective planes. Rend. Sem. Mat. Brescia 77 (1984), 367383.Google Scholar
[5]Hirschfeld, J. W. P.. Ovals in Desarguesian planes of even order. Ann. Mat. Pura Appl. 102 (1975), 7989.CrossRefGoogle Scholar
[6]Hirschfeld, J. W. P.. Projective Geometries over Finite Fields (Oxford University Press, 1979).Google Scholar
[7]Hirschfeld, J. W. P.. Maximum sets in finite projective spaces. In Surveys in Combinatorics, London Math. Soc. Lecture Note Series no. 82 (Cambridge University Press, 1983), pp. 5576.CrossRefGoogle Scholar
[8]Hirschfeld, J. W. P.. Finite Projective Spaces of Three Dimensions (Oxford University Press, 1985).Google Scholar
[9]Korchmaros, G.. Alcune questioni riguardanti le geometrie combinatorie. Archi ed ovali dei piani finiti. Quad. Sem. Geom. Comb. Univ. Boma 67 (1987), 137.Google Scholar
[10]Lidl, R. and Niederreiter, H.. Finite Fields. Encyclopedia of Mathematics and its Applications, vol. 20 (Cambridge University Press, 1983).Google Scholar
[11]Migliori, G.. Insiemi di tipo (0, 2,q/2) in un piano proiettivo e sistemi di terne di Steiner. Rend. Mat. Appl. 7 (1987), 7782.Google Scholar
[12]Mills, W. H.. Polynomials with minimal value sets. Pacific J. Math. 14 (1964), 225241.CrossRefGoogle Scholar
[13]Olanda, D. and Lo Re, P. M.. On (0, 2, 4)-semiaffine planes. Proceedings of the Conference Combinatorics '88, Ravello 1988. (To appear.)Google Scholar
[14]Payne, S. E.. A complete determination of translation ovoids in finite Desarguesian plane. Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. 51 (1971), 328331.Google Scholar
[15]Payne, S. E.. Hyperovals and generalized quadrangles. In Finite Geometries, Lecture Notes in Pure and Applied Math. vol. 103 (Marcel Dekker, 1985), pp. 251270.Google Scholar
[16]Segre, B.. Le geometrie di Galois. Ann. Mat. Pura Appl. 48 (1959), 197.CrossRefGoogle Scholar
[17]Segre, B.. Ovali e curve σ nei piani di Galois di caratteristica due. Atti Accad. Naz. Lincei Rend. Cl. Sci. Fis. Mat. Natur. 32 (1962), 785790.Google Scholar
[18]Segre, B.. Introduction to Galois geometries (edited by Hirschfeld, J. W. P.). Atti Accad. Naz. Lincei. Mem. Cl. Sci. Fis. Mat. Natur. 8 (1967), 133236.Google Scholar
[19]Segre, B. and Bartocci, U.. Ovali ed altre curve nei piani di Galois di caratteristica due. Ada Arith. 8 (1971), 423449.CrossRefGoogle Scholar
[20]Tallini, G.. Some new results on sets of type (m, n) in projective planes. J. Geom. 29 (1987), 191199.CrossRefGoogle Scholar
[21]Tallini, G.. Linear codes associated with geometric structures. Resultate Math. 12 (1987), 411422.CrossRefGoogle Scholar
[22]Tallini, G.. Odd and even type sets in Steiner systems. In Proceedings of Second Internal. Catania Combinatorial Conference Graphs, Designs and Combinatorial geometries (Catania, 1989), Le matematiche (Catania). (To appear.)Google Scholar
[23]Tallini Scafati, M.. Recent results on (m, n) type k-sets in an affine plane αq. J. Geom. 29 (1987), 94100.CrossRefGoogle Scholar
[24]Thas, J. A., Payne, S. E. and Gevaert, H.. A family of ovals with few collineations. European J. Combin. 9 (1988), 353362.CrossRefGoogle Scholar
[25]Tits, J.. Ovoides á translations. Rend. Mat. Appl. 21 (1962), 3759.Google Scholar