Proprietà grafiche caratterizzanti le quadriche ellittiche di PG(3,q)
Received: February 20, 1997.
Classificazione AMS 51E20
Summary We prove that a k-set K of PG(3,q) with k ≤ q2 + 1
of class [0, m, n,]1 with respect to the lines, such that at the most q+1 m-secant lines meet at each point of K, is a (q2+1)-cap and hence, if q is odd, is an elliptic quadric.