A characterization of multiple (n-k)-blocking sets in projective spaces of square order

In [10], it was shown that small t-fold (n - k)-blocking sets in PG(n, q), q = p(h), p prime, h >= 1, intersect every k-dimensional space in t (mod p) points. We characterize in this article all t-fold (n k)-blocking sets in PG(n, q), q square, q >= 661, t < c(p)q(1/6)/2, vertical bar B vertical bar < tq(n-k) + 2tq(n-k-1) root q, intersecting every k-dimensional space in t (mod root q) points.

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