Giuseppe Veronese and Ernst Witt -- Neighbours in PG(5,3)
arXiv:1210.1926 · doi:10.1007/s000100050009
Abstract
Let be a point of the Veronese surface $\Vcal$ in \PG53. Then thereare four conics of $\Vcal$ through . We show that the internal points of those conics form a 12-cap which is a point model for Witt's 5- design. In fact, this construction is "dual" to a similar construction that has been established by the author. We give an explicit parametrization of the cap $\Kcal$; the domain is a dual affine plane which arises from \PG23 by removing one point. Thus, as a by--product, we obtain an easy approach to the extended ternary Golay code . Finally, we discuss some other procedures that yield 12-sets of points from the Veronese surface.