IJPAM: Volume 70, No. 5 (2011)

WHEN A FINITE SUBSET
COMPUTES THE -RANK OF SOME ?

E. Ballico
Department of Mathematics
University of Trento
38 123 Povo (Trento) - Via Sommarive, 14, ITALY
e-mail: ballico@science.unitn.it

Abstract. Let be an integral and projective variety. For any the -rank of is the minimal cardinality of a set such that ; any such with minimal cardinality is said to compute the -rank of . Fix . Here we give onditions on and which imply the existence of such that compute the -rank of .

AMS Subject Classification: 14N05

Key Words and Phrases: -rank