Spreads of T2(o), α-flocks and Ovals

We establish a representation of a spread of the generalized quadrangle T2(0), o an oval of PG(2, q), q even, in terms of a certain family of q ovals of PG(2, q) and investigate the properties of this representation. Using this representation we show that to every flock of a translation oval cone in PG(3, q) (α-flock), q even, there corresponds a spread of T2(o) for an oval o determined by the α-flock. This gives constructions of new spreads of T2(o), for certain ovals o, and in some cases solves the existence problem for spreads. It also provides a geometrical characterization of the ovals associated with a flock of a quadratic cone.

[1]  Cheryl E. Praeger,et al.  Ovoids and Translation Ovals , 1997 .

[2]  Joseph A. Thas,et al.  Generalized Quadrangles and Flocks of Cones , 1987, Eur. J. Comb..

[3]  Stan E. Payne A Tensor Product Action on q-Clan Generalized Quadrangles with $q=2^e$ , 1994 .

[4]  Tim Penttila,et al.  Ovals in Translation Hyperovals and Ovoids , 1997, Eur. J. Comb..

[5]  Tim Penttila,et al.  Subquadrangles of Generalized Quadrangles of Order (q2, q), q Even , 2001, J. Comb. Theory, Ser. A.

[6]  Tim Penttila,et al.  Ovoids ofPG(3, 16) are elliptic quadrics, II , 1990 .

[7]  Joseph A. Thas,et al.  A Result on Spreads of the Generalized Quadrangle T2(O), with Oan Oval Arising from a Flock, and Applications , 2001, Eur. J. Comb..

[8]  J. Hirschfeld Projective Geometries Over Finite Fields , 1980 .

[9]  Tim Penttila A plane representation of ovoids , 1999 .

[10]  G. Royle,et al.  Classification of ovoids inPG(3, 32) , 1994 .

[11]  Tim Penttila,et al.  Ovoids with a pencil of translation ovals , 1996 .

[12]  Stanley E. Payne SYMMETRIC REPRESENTATIONS OF NONDEGENERATE GENERALIZED n-GONS , 1968 .

[13]  Tim Penttila,et al.  A new hyperoval inPG(2, 32) , 1992 .

[14]  P. Dembowski Finite geometries , 1997 .

[15]  Hendrik Van Maldeghem Ovoids and Spreads Arising from Involutions , 1998 .

[16]  David G. Glynn Plane representations of ovoids , 1998 .

[17]  Joseph A. Thas,et al.  Ovoidal translation planes , 1972 .

[18]  Tim Penttila,et al.  Flocks and ovals , 1996 .

[19]  J. Tits Ovoßdes et Groupes de Suzuki , 1962 .

[20]  William Cherowitzo,et al.  α-Flocks and Hyperovals , 1998 .